KR101730867B1 - Direct Oxidative Arylation of C(sp3)-H Bonds Adjacent to Oxygen of Ethers and Alcohols - Google Patents
Direct Oxidative Arylation of C(sp3)-H Bonds Adjacent to Oxygen of Ethers and Alcohols Download PDFInfo
- Publication number
- KR101730867B1 KR101730867B1 KR1020150122271A KR20150122271A KR101730867B1 KR 101730867 B1 KR101730867 B1 KR 101730867B1 KR 1020150122271 A KR1020150122271 A KR 1020150122271A KR 20150122271 A KR20150122271 A KR 20150122271A KR 101730867 B1 KR101730867 B1 KR 101730867B1
- Authority
- KR
- South Korea
- Prior art keywords
- nmr
- mhz
- cdcl
- alcohols
- compound
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/04—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
- C07D307/06—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to ring carbon atoms
- C07D307/08—Preparation of tetrahydrofuran
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/15—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively
- C07C29/151—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases
- C07C29/153—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases characterised by the catalyst used
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/60—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by elimination of -OH groups, e.g. by dehydration
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C31/00—Saturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
- C07C31/02—Monohydroxylic acyclic alcohols
- C07C31/12—Monohydroxylic acyclic alcohols containing four carbon atoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D309/00—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings
- C07D309/02—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D317/00—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms
- C07D317/08—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention relates to an arylation process for ethers or alcohols via C (sp 3 ) -H bond activity. More particularly, the present invention relates to an arylation process for the etherification of aldehydes or alcohols with -B OH) 2 can be synthesized by reacting a phenol having no functional group such as -OH (OH) 2 with a transition metal catalyst to form a new type of sp 3 CH bond. Such an arylation method requires addition of a -B (OH) 2 functional group to the benzene ring There is an advantage that a phenol derivative or a naphthalene derivative which is commercially available can be reacted to directly connect an ether or an alcohol to a benzene ring containing an OH group.
Description
The present invention relates to a process for the arylation of ethers or alcohols via C (sp 3 ) -H bond activity.
Recently, the direct activation of CH bond, which has been widely studied, is attracting attention as an environmentally friendly synthesis method because it reduces the introduction of functional groups and reduces the reaction process and the use of metal catalyst. Due to this importance, studies on sp 3 CH bond activation in the neighborhood of nitrogen, oxygen and sulfur elements have become a hot issue in organic chemistry. Nevertheless, many studies on sp 3 CH bond activation of neighboring nitrogen atoms have been carried out, but there is still a lack of research on sp 3 CH bond activation of oxygen atoms.
It is an object of the present invention to provide an arylation process for ethers or alcohols via C (sp 3 ) -H bond activity.
In order to achieve the above object, the present invention is ethers or in the arylation process of alcohol, tert as the oxidant t-butyl hydroperoxide (TBHP) and catalyst as Pd (OAc) 2 and Cu (OTf) 2 exist under ether The present invention provides a method for the arylation of an ether or an alcohol, which comprises subjecting a compound selected from the group consisting of a phenol derivative and a naphthalene derivative to a cross-linking-dehydrogenation coupling reaction.
According to the arylation method of the present invention, a new type of sp 3 CH bond can be synthesized by reacting ethers or alcohols with phenols having no functional groups such as -B (OH) 2 under a transition metal catalyst, (OH) 2 functional groups do not need to be introduced into the benzene ring, and commercially available phenol derivatives or naphthalene derivatives are reacted to directly link the ethers or alcohols with the benzene ring containing OH groups There are advantages to be able to.
The present inventors have found that by using T-butyl hydroperoxide (TBHP) as an oxidizing agent and by using Pd (OAc) 2 and Cu (OTf) 2 as catalysts, an ether containing tetrahydrofuran or an alcohol containing methanol, The inventors have discovered an arylation method capable of introducing an aryl group to an ether or an alcohol through C (sp 3 ) -H bond activity through a dehydrogenation coupling reaction, thereby completing the present invention.
[Reaction Scheme 1]
Of a butyl hydroperoxide (TBHP) and catalytic Pd (OAc) 2 and Cu (OTf) 2 ethers or alcohols in the presence - The present invention, in the arylation process of ethers or alcohols, as the oxidizing agent T There is provided a method for arylation of an ether or an alcohol characterized in that any one of the compounds and a derivative selected from a phenol derivative or a naphthalene derivative is subjected to a cross-linking-dehydrogenation coupling reaction.
The crosslinking-dehydrogenation coupling reaction can be carried out at a temperature of 50 to 80 ° C under a nitrogen atmosphere for 2 to 24 hours, and when the condition is exceeded, the yield of the desired product is low or other by-products are generated Can be caused.
The ethers may be selected from the group consisting of tetrahydrofuran, 1,3-dioxolane, tetrahydropyran and 1,4-dioxane, but are not limited thereto.
The alcohols may be selected from the group consisting of C1 to C4 alcohols and 2-methyl-1-propanol, but are not limited thereto.
Examples of the phenol derivative include 2,4-dihydroxyacetophenone, 2,4-dihydroxypropiophenone, 2,4-dihydroxybenzophenone, 1- (2,4-dihydroxyphenyl) 2,4-dihydroxybenzoate, ethyl 2,4-dihydroxybenzoate, ethyl 2,4-dihydroxy-6-methylbenzoate, propyl 2,4-dihydroxybenzoate, Dihydroxybenzoate, butyl 2,4-dihydroxybenzoate, and 2,4-dihydroxybenzaldehyde, but is not limited thereto.
Dihydroxy-3-phenylnaphthalene-1 (4H) -one, 1,3-dihydroxy-9H-xanthin-9-one, 1,3-dihydroxy- Naphthol, (6-hydroxynaphthalen-2-yl) (phenyl) methanone, 1,4-dihydroxynaphthalene and 5-hydroxynaphthalene 4-naphthoquinone, and the like, but is not limited thereto.
Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.
According to the following Reaction Scheme 2, direct cross-linking coupling between tetrahydrofuran (THF, 1a) and 2,4-dihydroxyacetophenone (2a) was carried out in the presence of various oxidizing agents and catalysts, the equivalent amount of TBHP, as a catalyst, Pd (OAc) 2 (5 mol %) and Cu (OTf) when using 2 (25 mol%) in the high yield of 1- [2,4-dihydroxy-3- (tetrahydro- Furan-2-yl) phenyl] ethanone (3a). Hereinafter, the objective compound was synthesized using TBHP as an oxidizing agent, Pd (OAc) 2 and Cu (OTf) 2 as catalysts.
[Reaction Scheme 2]
All experiments were carried out under nitrogen atmosphere. For the TLC analysis, pre-coated silica gel plates (Art. 5554) with fluorescence indicator from Merck are used. Flash column chromatography was performed using silica gel 9385 (Merck). And 1 H NMR and 13 C NMR analyzes were recorded on a Varian VNS (300 MHz and 75 MHz) spectrometer in CDCl 3 using δ 7.24 and 77.23 ppm as solvent chemical shifts. IR analysis was performed using FTIR (BIO-RAD) and HRMS analysis was performed through the Korea Basic Science Research Institute. Structural analysis of the composite was carried out on a Bruker SMART APEX CCD diffractometer using graphite mono-color Mo-Kα radiation (λ = 0.71073 Å).
≪ Example 1 >
Pd (OAc) 2 (5.6 mg , 5 mol%), Cu (OTf) 2 (45 mg, 25 mol%), 2,4- dihydroxy-acrylic carbonyl (or naphthols in a dry reaction flask in an oven in a nitrogen atmosphere Butylhydroperoxide (TBHP, 5.0-6.0 M in decane, 0.1 mL, 0.6 mmol) and THF (or ethers and alcohols) (5.0 mL) mmol). The reaction mixture was stirred on an oil bath at 65 [deg.] C for 2-24 hours. Subsequently, the volatiles were removed under vacuum and the residue was purified by silica gel column chromatography (hexane: ethyl acetate = 15: 1) to give the desired product.
Scheme 3 below shows the chemical structures of the compounds 3a to 3j and the production method thereof.
[Reaction Scheme 3]
1) 1- [2,4-Dihydroxy-3- (tetrahydrofuran-2-yl) phenyl] ethanone (3a)
The compound was reacted with 2,4-dihydroxyacetophenone (2a) for 24 hours in accordance with the general synthesis method described above to obtain a compound in 62% yield (69 mg).
White solid; mp 100-102 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.2 (1H, s, OH), 7.50 (1H, d, J = 8.7 Hz), 6.34 (1H, d, J = 9.0 Hz), 5.26 (1H, (1H, m), 2.50 (3H, s), 2.08-1.99 (2H, m), 1.78-1.66 (1 H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 202.6, 163.0, 161.7, 131.2, 112.6, 111.8, 109.0, 78.8, 68.4, 32.6, 26.0, 25.3; IR (KBr):? = 3091, 1619, 1367, 1249, 1234, 803 cm -1 ; HR-MS (EI): m / z = 222.0891 (M +), calcd, for C 12 H 14 O 4: 222.0892.
2) 1- [2,4-Dihydroxy-3- (tetrahydrofuran-2-yl) phenyl] propan-
The compound was reacted with 2,4-dihydroxypropiophenone (2b) for 24 hours according to the general synthesis method described above to obtain a compound in 63% yield (74 mg).
White solid; mp 92-94 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.1 (1H, s, OH), 7.53 (1H, d, J = 9.0 Hz), 6.33 (1H, d, J = 8.6 Hz), 5.26 (1H, (2H, q, J = 6.0 Hz), 2.61-2.53 (1H, m), 2.08 (1H, dd, J = 8.9, 6.2 Hz), 4.16-4.08 -1.98 (2H, m), 1.78-1.65 (1H, m), 1.18 (3H, t, J = 7.5 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 205.4, 162.7, 161.7, 130.2, 112.0, 111.9, 108.9, 78.8, 68.4, 32.6, 30.9, 25.3, 8.6; IR (KBr):? = 3111, 1616, 1490, 1370, 1229, 1070, 791 cm -1 ; HRMS (EI): m / z = found: 236.1050 (M + ), calcd. for C 13 H 16 O 4: 236.1049.
3) [2,4-Dihydroxy-3- (tetrahydrofuran-2-yl) phenyl] - (phenyl) methanone (3c)
The compound was reacted with 2,4-dihydroxybenzophenone (2c) for 24 hours in accordance with the general synthesis method described earlier to obtain a compound in 67% yield (95 mg).
White solid; mp 88-90 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.3 (1H, s, OH), 7.60-7.57 (2H, m), 7.54-7.42 (3H, m), 7.37 (1H, d, J = 9.0 Hz ), 6.31 (1H, d, J = 9.0 Hz), 5.34 (1H, dd, J = 9.3, 6.3 Hz), 4.18-4.11 (1H, m), 3.97-3.90 1H, m), 2.11-2.01 (2H, m), 1.85-1.72 (1H, m); 13 C NMR (75 MHz, CDCl 3):? = 200.0, 163.2, 162.8, 138.2, 134.1, 131.2, 128.7, 128.1, 112.0, 111.8, 108.9, 78.8, 68.4, 32.6, 25.3; IR (KBr):? = 3176, 1611, 1492, 1347, 1260, 1046, 706 cm -1 ; HR-MS (EI): m / z = 284.1051 (M + ), calcd. for C 17 H 16 O 4: 284.1049.
4) 1- [2,4-Dihydroxy-3- (tetrahydrofuran-2-yl) phenyl] -2-phenylethanone (3d)
The compound was reacted with 1- (2,4-dihydroxyphenyl) -2-phenylethanone (2d) according to the general synthesis method described above for 24 hours to obtain a compound in a yield of 61% (91 mg).
Off-white solid; mp 77-78 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.1 (1H, s, OH), 7.56 (1H, d, J = 9.0 Hz), 7.26-7.16 (5H, m), 6.27 (1H, d, J (1H, m), 1.99-1.90 (1H, m), 8.83 (1H, d, J = 2H, m), 1.70-1.157 (1 H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 201.9, 163.1, 162.3, 134.4, 130.9, 129.2, 129.2, 128.6, 128.6, 126.9, 112.0, 111.9, 109.2, 78.7, 68.3, 44.5, 32.5, 25.3; IR (KBr):? = 3165, 1613, 1496, 1356, 1260, 1006, 1043, 732 cm -1 ; HR-MS (EI): m / z = 298.1203 (M + ), calcd. for C 18 H 18 O 4: 298.1205.
5) Methyl 2,4-dihydroxy-3- (tetrahydrofuran-2-yl) benzoate (3e):
Dihydroxybenzoate (2e) according to the general synthesis method described above for 24 hours to obtain a compound in 60% yield (71 mg).
White solid; mp 65-67 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 11.2 (1H, s, OH), 10.0 (1H, s, OH), 7.51 (1H, d, J = 8.7 Hz), 6.34 (1H, d, J M), 3.87 (3H, s), 2.60-2.52 (IH, m) m), 2.09-1.99 (2H, m), 1.80-1.67 (1 H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 170.7, 162.2, 160.2, 129.9, 111.7, 109.2, 104.1, 78.8, 68.4, 51.8, 32.6, 25.4; IR (KBr):? = 3184, 1663, 1498, 1441, 1313, 1261, 1047, 794 cm -1 ; HR-MS (EI): m / z = 238.0844 (M + ), calcd. for C 12 H 14 O 5 : 238.0841.
6) Ethyl 2,4-dihydroxy-3- (tetrahydrofuran-2-yl) benzoate (3f):
The compound was reacted with ethyl 2,4-dihydroxybenzoate (2f) for 24 hours according to the general synthesis method described earlier to obtain a compound in 55% yield (69 mg).
White solid; mp 70-71 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 11.3 (1H, s, OH), 9.99 (1H, s, OH), 7.63 (1H, d, J = 9.0 Hz), 6.34 (1H, d, J M), 2.62 (1H, d, J = 6.0 Hz), 5.28 (1H, dd, J = -2.52 (1H, m), 2.08-1.99 (2H, m), 1.80-1.67 (1H, m), 1.36 (3H, t, J = 7.2 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 170.4, 162.2, 160.2, 129.9, 111.7, 109.1, 104.3, 78.9, 68.4, 60.9, 32.7, 25.4, 14.2; IR (KBr):? = 3205, 2982, 1660, 1498, 1334, 1259 cm -1 ; HR-MS (EI): m / z = 252.0998 (M + ), calcd. for C 13 H 16 O 5: 252.0998.
7) Ethyl 2,4-dihydroxy-6-methyl-3- (tetrahydrofuran-2-yl) benzoate (3 g)
According to the above general synthesis method, ethyl 2,4-dihydroxy-6-methylbenzoate (2 g) was reacted for 24 hours to obtain a compound in 57% yield (76 mg).
White solid; mp 100-102 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 9.91 (1H, s, OH), 6.19 (1H, s), 5.24 (1H, dd, J = 9.6, 6.3 Hz), 4.35 (2H, q, J = 7.2 Hz), 4.15-4.07 (1H, m), 3.93-3.85 (1H, m), 2.60-2.50 (1H, m), 2.43 1.63 (1H, m), 1.37 (3H, t, J = 6.9 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 171.7, 161.4, 160.0, 141.4, 112.0, 109.2, 103.6, 78.8, 67.8, 60.6, 32.3, 24.9, 23.7, 13.7; IR (KBr):? = 3412, 2982, 1644, 1586, 1448, 1255, 816 cm -1 ; HR-MS (EI): m / z = 266.1154 (M + ), calcd. for C 14 H 18 O 5: 266.1154.
8) propyl 2,4-dihydroxy-3- (tetrahydrofuran-2-yl) benzoate (3h):
The compound was reacted with propyl 2,4-dihydroxybenzoate (2h) for 24 hours according to the general synthesis method described earlier to obtain a compound in 52% yield (64 mg).
White solid; mp 71-72 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 11.3 (1H, s, OH), 9.99 (1H, s, OH), 7.63 (1H, d, J = 9.0 Hz), 6.34 (1H, d, J = 9.0 Hz), 5.28 (1H, dd, J = 9.3,6.0 Hz), 4.23 (2H, t, J = 6.6 Hz), 4.16-4.09 (1H, m), 3.94-3.87 -2.52 (1H, m), 2.08-1.99 (2H, m), 1.81-1.67 (3H, m), 0.99 (3H, t, J = 7.2 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 170.4, 162.2, 160.2, 129.8, 111.7, 109.1, 104.3, 78.9, 68.4, 66.4, 32.6, 25.4, 22.0, 10.3; IR (KBr): n = 3221, 2970, 1657, 1497, 1340, 1260, 1049, 757 cm -1 ; HR-MS (EI): m / z = 266.1155 (M + ), calcd. for C 14 H 18 O 5: 266.1154.
9) butyl 2,4-dihydroxy-3- (tetrahydrofuran-2-yl) benzoate (3i):
The compound was reacted with butyl 2,4-dihydroxybenzoate (2i) for 24 hours in accordance with the general synthesis method described above to obtain a compound in 40% yield (56 mg).
White solid; mp 60-62 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 11.3 (1H, s, OH), 10.0 (1H, s, OH), 7.62 (1H, d, J = 8.7 Hz), 6.34 (1H, d, J (1H, m), 2.62 (1H, d, J = 8.7 Hz), 5.27 (1H, dd, J = 9.3, 6.3 Hz), 4.27 -2.52 (1H, m), 2.10-1.99 (2H, m), 1.80-1.67 (3H, m), 1.50-1.38 (2H, m), 0.95 (3H, t, J = 7.2 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 170.4, 162.1, 160.2, 129.8, 111.6, 109.1, 104.3, 78.9, 68.4, 64.7, 32.6, 30.6, 25.4, 19.1, 13.6; IR (KBr):? = 3392, 3232, 2960, 1660, 1497, 1337, 1258, 1147, 753 cm -1 ; HR-MS (EI): m / z = 280.1309 (M + ), calcd. for C 15 H 20 O 5: 280.1311.
10) 2,4-Dihydroxy-3- (tetrahydrofuran-2-yl) benzaldehyde (3j):
Dihydroxybenzaldehyde (2j) according to the general synthesis method described above for 24 hours to obtain a compound in 50% yield (52 mg).
White solid; mp 40-42 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 11.7 (1H, s, OH), 10.3 (1H, s), 9.6 (1H, s, OH), 7.28 (1H, d, J = 8.7 Hz), (1H, m), 2.61-2.55 (1H, m), 6.43 (1H, d, J = m), 2.09-2.00 (2H, m), 1.77-1.73 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 194.3, 163.9, 160.9, 134.1, 114.0, 111.6, 110.2, 78.4, 68.5, 32.6, 25.3; IR (neat): n = 3163, 2979, 1640, 1494, 1333, 1224, 1047, 774 cm -1 ; HR-MS (EI): m / z = 208.0736 (M + ), calcd. for C 11 H 12 O 4: 208.0736.
Scheme 4 below shows the chemical structure and the preparation method of the compounds 5a to 5f.
[Reaction Scheme 4]
11) 5,7-Dihydroxy-2-phenyl-6- (tetrahydrofuran-2-yl) -4H-chromen-
Dihydroxy-3-phenylnaphthalene-1 (4H) -one (4a) according to the general synthesis method described above for 12 hours to obtain a compound in 50% yield (81 mg).
Light yellow solid; mp 155-157 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 13.1 (1H, s, OH), 10.2 (1H, s, OH), 7.87-7.83 (2H, m), 7.52-7.45 (3H, m), 6.61 (1H, s), 6.43 (1H, s), 5.31 (1H, dd, J = 9.6, 6.0 Hz), 4.19-4.11 (1H, m), 3.98-3.90 , < / RTI > m), 2.12-2.02 (2H, s), 1.84-1.71 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 182.5, 163.8, 162.9, 158.5, 156.6, 131.7, 131.3, 129.0, 126.2, 108.1, 105.5, 104.3, 95.0, 78.4, 68.4, 32.6, 25.4; IR (KBr):? = 3429, 2962, 1633, 1587, 1372, 1163 cm -1 ; HR-MS (EI): m / z = 324.1000 (M + ), calcd. for C 19 H 16 O 5: 324.0998.
12) 1,3-Dihydroxy-2- (tetrahydrofuran-2-yl) -9H-xanthin-
Dihydroxy-9H-xanthin-9-one (4b) according to the general synthesis method described above for 6 hours to obtain a compound in 57% yield (85 mg).
Light yellow solid; mp 180-182 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.3 (1H, s, OH), 8.19 (1H, d, J = 6.6 Hz), 7.68-7.63 (1H, m), 7.39-7.29 (2H, m ), 6.34 (1H, s), 5.30 (1H, dd, J = 9.3, 6.0 Hz), 4.19-4.11 (1H, m), 3.98-3.90 (1H, m), 2.65-2.55 2.12-2.02 (2 H, s), 1.84-1.71 (1 H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 180.7 164.2, 159.9, 156.6, 155.9, 134.8. 125.7, 123.7, 120.5, 117.5, 107.0, 102.7, 95.1, 78.5, 68.4, 32.6, 25.4; IR (KBr):? = 3422, 1615, 1456, 1292, 1148, 758 cm -1 ; HR-MS (EI): m / z = 298.0841 (M + ), calcd. for C 17 H 14 O 5: 298.0841.
13) 1,3-Dihydroxy-5-methoxy-2- (tetrahydrofuran-2-yl) -9H-xanthan-
Dihydroxy-5-methoxy-9H-xanthin-9-one (4c) according to the general synthesis method described above for 6 hours to obtain a compound in 45% yield (74 mg).
Light yellow solid; mp 160-162 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.3 (1H, s, OH), 7.33 (1H, d, J = 8.1 Hz), 7.24-7.14 (2H, m), 6.44 (1H, s), (1H, m), 2.09 (1H, d, J = 9.6, 6.0 Hz), 4.15-4.08 (1H, m), 3.96 (3H, s), 3.95-3.87 1.99 (2H, s), 1.81-1.68 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 180.7, 164.2, 159.7, 156.4, 148.2, 146.2, 123.3, 121.3, 116.6, 115.6, 107.2, 102.7, 95.4, 78.5, 68.4, 56.4, 32.6, 25.4; IR (KBr):? = 3382, 1648, 1583, 1496, 1273, 751 cm -1 ; HR-MS (EI): m / z = 328.0946 (M + ), calcd. for C 18 H 16 O 6: 328.0947.
14) 2- (Tetrahydrofuran-2-yl) naphthalen-1-ol (5d):
According to the general synthesis described above, 1-naphthol (4d) was reacted for 24 hours to obtain a compound in 64% yield (68 mg).
Off-white solid; mp 47-50 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 9.50 (1H, s, OH), 8.28-8.25 (1H, m), 7.75-7.72 (1H, m), 7.47-7.43 (2H, m), 7.32 (1H, d, J = 8.4 Hz), 7.02 (1H, d, J = 8.4Hz), 5.21-5.16 (1H, m), 4.22-4.14 2.45-2.38 (1H, s), 2.12-1.97 (3H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 150.8, 133.6, 127.1, 126.1, 125.4, 125.0, 124.6, 122.1, 118.8, 117.3, 82.8, 68.6, 33.7, 25.4; IR (KBr):? = 3299, 1575, 1392, 1041, 807 cm -1 ; HR-MS (EI): m / z = 214.0995 (M +), calcd. for C14H14O2: 214.0994.
15) 1- (Tetrahydrofuran-2-yl) naphthalen-2-ol (5e):
The compound was reacted with 2-naphthol (4e) for 12 hours in accordance with the general synthesis method described above to obtain a compound in 61% yield (65 mg).
Off-white solid; mp 88-90 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 9.82 (1H, s, OH), 7.75 (1H, d, J = 8.1 Hz), 7.67-7.63 (2H, m), 7.45-7.40 (1H, m ), 7.32-7.27 (1H, m), 7.09 (1H, d, J = 8.7 Hz), 5.72 (1H, dd, J = 9.3, 6.6 Hz), 4.32-4.25 (1H, m), 4.03-3.95 1H, m), 2.67-2.57 (1H, m), 2.18-2.09 (2H, m), 1.97-1.84 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 153.6, 131.5, 129.2, 128.7, 128.5, 126.3, 122.6, 121.2, 119.8, 114.5, 80.9, 68.4, 33.5, 25.6; IR (KBr):? = 3241, 2976, 1622, 1465, 1228, 1040, 817 cm -1 ; HR-MS (EI): m / z = (M @ + ), calcd. for C 14 H 14 O 2: 214.0994.
16) [6-Hydroxy-5- (tetrahydrofuran-2-yl) naphthalen-2-yl] - (phenyl) methanone (5f)
(6-hydroxynaphthalen-2-yl) (phenyl) methanone (4f) according to the general synthesis method described above for 6 hours to obtain a compound in 66% yield (105 mg).
White solid; mp 150-152 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 10.0 (1H, s, OH), 8.15 (1H, s), 7.93-7.90 (1H, m), 7.83-7.80 (2H, m), 7.72-7.68 (2H, m), 7.61-7.55 (1H, m), 7.50-7.45 (2H, m), 7.12 (1H, d, J = 8.7 Hz), 5.70 4.32-4.25 (1H, m), 4.04-3.96 (1H, s), 2.69-2.59 (1H, s), 2.20-2.10 (2H, m), 1.96-1.83 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 196.2, 156.1, 138.0, 133.7, 132.8, 132.0, 131.6, 130.8, 129.8, 128.2, 127.2, 126.4, 121.5, 120.8, 114.9, 80.7, 68.5, 33.5, 25.6 ; IR (KBr): n = 3394, 1650, 1618, 1281, 1233, 752 cm < -1 & gt ;; HRMS (EI): m / z = 318.1252 (M +), calcd, for C 21 H 18 O 3: 318.1256.
Scheme 5 below shows the chemical structures of the compounds 7a to 7k and the preparation method thereof.
[Reaction Scheme 5]
17) 2- (Tetrahydrofuran-2-yl) naphthalene-1,4-dione (7a)
The compound was reacted with 1,4-dihydroxynaphthalene (6a) and tetrahydrofuran (5.0 mL) for 6 hours according to the general synthesis method described above to obtain the compound in 67% yield (76 mg).
Brown solid; mp 73-75 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 8.06-8.03 (2H, m), 7.72-7.69 (2H, m), 7.07 (1H, s), 5.00 (1H, t, J = 6.9 Hz), 4.06-3.99 (1H, m), 3.95-3.83 (1H, m), 2.54-2.43 (1H, m), 2.06-1.84 (2H, m), 1.74-1.65 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 185.2, 185.0, 152.3, 133.8, 133.5, 132.2, 132.0, 126.2, 126.1, 74.8, 68.7, 32.8, 25.7; IR (KBr): n = 2979, 1662, 1589, 1300, 1247, 1063, 781 cm -1 ; HR-MS (EI): m / z = 228.0789 (M + ), calcd. for C 14 H 12 O 3: 228.0786.
18) 2- (1,3-Dioxolan-2-yl) naphthalene-1,4-dione (7b)
The compound was reacted with 1,4-dihydroxynaphthalene (6a) and 1,3-dioxolane (5.0 mL) for 4 hours according to the general synthesis method described above to obtain a compound in 33% yield (26 mg).
Pale yellow solid; mp 78-80 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 8.08-8.03 (2H, m), 7.77-7.72 (2H, m), 7.06 (1H, s), 5.14 (1H, s), 5.13-5.08 (1H , m), 5.03 (1H, s), 4.41 (1H, t, J = 8.4 Hz), 3.70 (1H, dd, J = 8.4, 5.4 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 185.1, 184.7, 148.9, 134.1, 133.7, 132.8, 131.9, 131.8, 126.3, 126.2, 95.5, 71.7, 70.2; IR (KBr):? = 2359, 1663, 1244, 1077 cm -1 ; HRMS (EI): m / z = 230.0583 (M + ), calcd. for C 13 H 10 O 4: 230.0579.
19) 2- (Tetrahydro-2H-pyran-2-yl) naphthalene- 1,4-dione (7c)
The compound was reacted with 1,4-dihydroxynaphthalene (6a) and tetrahydropyran (5.0 mL) for 6 hours in accordance with the general synthesis method described earlier to obtain a compound in 45% yield (54 mg).
Brown solid; mp 60-62 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 8.06-8.02 (2H, m), 7.72-7.68 (2H, m), 7.03 (1H, s), 4.53-4.49 (1H, m), 4.14-4.09 (1H, m), 3.63-3.55 (1H, m), 2.04-2.00 (1H, m), 1.91-1.88 ; 13 C NMR (75 MHz, CDCl 3 ):? = 185.1, 184.1, 151.7, 133.6, 133.5, 133.1, 132.1, 131.8, 126.3, 125.9, 73.3, 68.7, 32.9, 25.7, 23.5; IR (KBr):? = 2938, 2853, 1662, 1299, 1244, 1088 cm -1 ; HR-MS (EI); m / z = 242.0944 (M < + & gt ; ), calcd. for C 15 H 14 O 3: 242.0943.
20) 2- (1,4-dioxan-2-yl) naphthalene-1,4-dione (7d)
The compound was reacted for 2 hours with 1,4-dihydroxynaphthalene (6a) and 1,4-dioxane (5.0 mL) according to the general synthesis method described above to give 47% yield (57 mg).
Yellow solid; mp 110-102 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 8.06-8.02 (2H, m), 7.72-7.69 (2H, m), 7.08 (1H, s), 4.84-4.80 (1H, m), 4.15-4.11 (1H, m), 3.95-3.84 (2H, m), 3.81-3.77 (1H, m), 3.68-3.60 (1H, m), 3.25-3.18 (1H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 184.7, 183.8, 147.2, 134.8, 133.9, 133.7, 131.9, 131.8, 126.4, 126.2, 71.9, 71.5, 66.9, 66.4; IR (KBr):? = 2990, 1763, 1664, 1242 cm -1 ; HR-MS (EI): m / z = 244.0735 (M + ), calcd. for C 14 H 12 O 4: 244.0736.
21) Compound 7e:
Hydroxy-1,4-naphthoquinone (6b) and 1,4-dioxane (5.0 mL) were reacted for 4 hours according to the general synthesis method described above to obtain an isomeric isomeric 1: % Yield (60 mg).
Brown solid; mp 155-157 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 11.9 (1H, s), 11.8 (1H, s), 6.62-7.57 (4H, m), 7.27-7.23 (2H, m), 7.07 (2H, s ), 4.85-4.80 (2H, m), 4.19-4.12 (2H, m), 3.97-3.79 (6H, m), 3.70-3.61 (2H, m), 3.28-3.18 (2H, m); 13 C NMR (75 MHz, CDCl 3 ):? = 189.9, 189.0, 183.9, 183.0, 161.6, 161.2, 148.5, 147.2, 136.6, 136.2, 135.7, 134.7, 131.8, 131.7, 124.5, 124.3, 119.2, , 71.9, 71.5, 71.5, 71.4, 67.0, 66.9, 66.3; IR (KBr):? = 2972, 1763, 1643, 1243, 1113 cm -1 ; HR-MS (EI): m / z = 260.0685 (M + ), calcd. for C 14 H 12 O 5: 260.0685.
22) 2- (hydroxymethyl) naphthalene-1,4-dione (7f):
The compound was obtained in 60% yield (56 mg) by reaction of 1,4-dihydroxynaphthalene (6a) with methanol (5.0 mL) for 18 hours using TBHP (0.3 mL) according to the general synthesis described above.
Brown solid; mp 90-91 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 8.07-8.04 (2H, m), 7.76-7.69 (2H, m), 7.00 (1H, s), 4.67 (2H, s), 2.02 (1H, s , OH); 13 C NMR (75 MHz, CDCl 3 ):? = 185.3, 185.0, 149.2, 134.0, 133.7, 133.3, 131.9, 126.2, 59.8; IR (KBr):? = 3394, 1663, 1591, 1300, 1249, 1058, 777 cm -1 ; HRMS (EI): m / z = 188.0476 (M + ), calcd. for C 11 H 8 O 3: 188.0473.
23) 2- (hydroxyethyl) naphthalene-1,4-dione (7 g):
A 60% yield (60 mg) of a compound was obtained by reaction of 1,4-dihydroxynaphthalene (6a) with ethanol (5.0 mL) at 65 ° C using TBHP (0.3 mL) according to the above general synthesis method for 18 hours .
Brown liquid; 1 H NMR (300 MHz, CDCl 3): δ = 8.09-8.02 (2H, m), 7.71-7.69 (2H, m), 6.98 (1H, s), 4.98 (1H, q, J = 6.0 Hz), 2.46 (1H, s, OH), 1.47 (3H, d, J = 5.7 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 185.3, 185.2, 152.9, 133.9, 133.7, 132.7, 132.1, 131.8, 126.3, 126.0, 65.0, 22.6; IR (neat):? = 3482, 2975, 2931, 1663, 1595, 1299, 1251, 719 cm -1 ; HR-MS (EI): m / z = 202.0629 (M + ), calcd. for C 12 H 10 O 3 : 202.0630.
24) 2- (1-ethoxyethyl) naphthalene-1,4-dione (7h):
According to the above general synthesis method, 53% yield (61 mg) of a compound was obtained by reacting TBHP (0.3 mL) with 1,4-dihydroxynaphthalene (6a) and ethanol (5.0 mL) at 100 ° C for 24 hours .
Brown liquid; 1 H NMR (300 MHz, CDCl 3): δ = 8.08-8.05 (2H, m), 7.73-7.70 (2H, m), 7.02 (1H, s), 4.66 (1H, q, J = 6.3 Hz), 3.48 (2H, q, J = 6.3 Hz), 1.38 (3H, d, J = 6.6 Hz), 1.22 (3H, t, J = 7.2 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 185.3, 185.0, 152.7, 133.8, 133.6, 132.8, 132.2, 131.9, 126.3, 126.1, 71.1, 64.8, 21.9, 15.3; IR (neat):? = 2978, 1663, 1595, 1299, 1249, 1111 cm -1 ; HR-MS (EI): m / z = 230.0944 (M + ), calcd. for C 14 H 14 O 3: 230.0943.
25) 2- (1-Hydroxypropyl) naphthalene-1,4-dione (7i):
According to the general synthesis described above, 51% yield (55 mg) of the compound was obtained by reaction between 1,2-dihydronaphthalene and propanol (5.0 mL) using TBHP (0.3 mL) for 20 hours.
Brown liquid; 1 H NMR (300 MHz, CDCl 3): δ = 8.05-8.01 (2H, m), 7.73-7.69 (2H, m), 6.95 (1H, s), 4.74 (1H, dd, J = 6.9, 4.8 Hz ), 2.50 (1H, s, OH), 1.89-1.78 (1H, m), 1.73-1.63 (1H, m), 1.00 (3H, t, J = 7.5 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 185.4, 185.1, 151.7, 133.9, 133.7, 133.6, 132.2, 131.8, 126.4, 126.1, 70.3, 29.5, 9.86; IR (neat):? = 3465, 2969, 1662, 1626, 1302, 1049, 777 cm -1 ; HRMS (EI): m / z = 216.0790 (M + ), calcd. for C 13 H 12 O 3: 216.0786.
26) 2- (1-Hydroxybutyl) naphthalene-1,4-dione (7j):
According to the general synthesis described above, 32% yield (37 mg) of the compound was obtained via reaction between 1,2-dihydronaphthalene and n-butanol (0.5 mL) in hexane (5.0 mL) using TBHP .
Brown liquid; 1 H NMR (300 MHz, CDCl 3): δ = 8.07-8.03 (2H, m), 7.75-7.70 (2H, m), 6.96 (1H, s), 4.81 (1H, dd, J = 7.2, 4.8 Hz ), 2.38 (1H, s, OH), 1.80-1.62 (2H, m), 1.54-1.42 (2H, m), 0.94 (3H, t, J = 7.2 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 185.5, 185.2, 152.1, 134.0, 133.8, 133.5, 127.4, 126.9, 126.5, 126.2, 69.1, 38.7, 18.9, 13.8; IR (neat): n = 3464, 2970, 1660, 1625, 1300, 1049 cm < -1 >; HR-MS (EI): m / z = 230.0939 (M + ), calcd. for C 14 H 14 O 3: 230.0943.
27) 2-isobutoxynaphthalene-1,4-dione (7k):
According to the above general synthesis method, 1,4-dihydroxynaphthalene (6a) and 2-methyl-1-propanol (1.0 mL) were reacted in benzene (5.0 mL) for 24 hours to obtain a compound in 40% yield .
Brown solid; mp 70-72 [deg.] C; 1 H NMR (300 MHz, CDCl 3): δ = 8.07-8.00 (2H, m), 7.70-7.62 (2H, m), 6.07 (1H, s), 3.70 (1H, d, J = 6.6 Hz), 2.23-2.14 (1H, m), 1.02 (6H, d, J = 6.6 Hz); 13 C NMR (75 MHz, CDCl 3 ):? = 185.0, 180.0, 159.8, 134.0, 133.1, 131.9, 131.1, 126.5, 126.0, 110.0, 75.5, 27.5, 19.0, 19.0; IR (KBr):? = 3057, 2957, 1674, 1598, 1248, 1016 cm -1 ; HR-MS (EI): m / z = 230.0942 (M + ), calcd. for C 14 H 14 O 3: 230.0943.
<Experimental Example 1>
In order to elucidate the mechanism of the prior arylation reaction, the arylation reaction was carried out in the presence of 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) and tert-butylhydroperoxide (TBHP) as radical trapping agents Respectively. Namely, Pd (OAc) 2 (5.6 mg, 5 mol%), Cu (OTf) 2 (45 mg, 25 mol%) and 2,4-dihydroxyacetophenone (125 mg, 0.75 mmol), THF (5.0 mL) and TEMPO or TBHP (5.0-6.0 M in decane, 0.1 mL, 0.6 mmol). The reaction mixture was stirred on an oil bath at 65 < 0 > C for 24 hours. The volatile components were then removed under vacuum and the residue was purified by silica gel chromatography (hexane: ethyl acetate = 100: 1).
As a result, when the TEMPO was used as a radical trapping agent as shown in the following Reaction Scheme 6, the desired compound 3a was not synthesized at all. When TBHP was used as the radical trapping agent, compound 8 (yield: 65 mg, 35% (Yield: 48 mg, 43%). The properties of compound 8 were consistent with reports of known literature (Chem. Commun. 2014, 50, 3623-3626).
[Reaction Scheme 6]
Thus, it is expected that the arylation reaction to the ether and alcohol via C (sp 3 ) -H bond activity will be carried out via the radical pathway.
While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
Claims (6)
As an oxidizing agent T-butyl hydroperoxide (TBHP) and a catalytic Pd (OAc) 2 and Cu (OTf) any one derivative selected from ethers or alcohols which a compound with a phenol derivative or a naphthalene derivative of under 2 there Linkage-dehydrogenation coupling reaction,
The ethers are any one selected from the group consisting of tetrahydrofuran, 1,3-dioxolane, tetrahydropyrane and 1,4-dioxane,
Wherein the alcohols are selected from the group consisting of C1 to C4 alcohols and 2-methyl-1-propanol.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150122271A KR101730867B1 (en) | 2015-08-31 | 2015-08-31 | Direct Oxidative Arylation of C(sp3)-H Bonds Adjacent to Oxygen of Ethers and Alcohols |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150122271A KR101730867B1 (en) | 2015-08-31 | 2015-08-31 | Direct Oxidative Arylation of C(sp3)-H Bonds Adjacent to Oxygen of Ethers and Alcohols |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20170026843A KR20170026843A (en) | 2017-03-09 |
| KR101730867B1 true KR101730867B1 (en) | 2017-04-28 |
Family
ID=58402345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020150122271A KR101730867B1 (en) | 2015-08-31 | 2015-08-31 | Direct Oxidative Arylation of C(sp3)-H Bonds Adjacent to Oxygen of Ethers and Alcohols |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101730867B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112645821A (en) * | 2021-01-22 | 2021-04-13 | 苏州大学 | Method for synthesizing aryl benzyl ether compound |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101286014B1 (en) | 2011-11-21 | 2013-07-18 | 광주과학기술원 | Direct CH arylation by using palladium-based catalyst |
-
2015
- 2015-08-31 KR KR1020150122271A patent/KR101730867B1/en active IP Right Grant
Non-Patent Citations (3)
| Title |
|---|
| 논문(J. Org. Chem., 2014, 79 (10), pp 4735-4742) |
| 논문(Proc Natl Acad Sci U S A. 2006, vol. 103, no. 24, pp. 8928-8933) |
| 논문(Synlett 2013, 24, pp. 2153-2159) |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20170026843A (en) | 2017-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Patra et al. | Sequential meta-C–H olefination of synthetically versatile benzyl silanes: effective synthesis of meta-olefinated toluene, benzaldehyde and benzyl alcohols | |
| Rao et al. | Gold-catalysed allylic alkylation of aromatic and heteroaromatic compounds with allylic alcohols | |
| Mirza-Aghayan et al. | Graphite oxide: a simple and efficient solid acid catalyst for the ring-opening of epoxides by alcohols | |
| Kobayashi et al. | The trityl perchlorate catalyzed Michael reaction | |
| Chan et al. | Bi (OTf) 3 catalyzed disproportionation reaction of cinnamyl alcohols | |
| Pradhan et al. | Synthesis of γ-Acetoxy β-Keto Esters Through Regioselective Hydration of γ-Acetoxy-α, β-alkynoates | |
| Zhang et al. | Alkoxyl-radical-mediated synthesis of functionalized allyl tert-(hetero) cyclobutanols and their ring-opening and ring-expansion functionalizations | |
| Pandit et al. | Direct Oxidative Arylation of C (sp3) H Bonds Adjacent to Oxygen of Ethers and Alcohols | |
| Laroche et al. | Basic anion-exchange resin-catalyzed aldol condensation of aromatic ketones with aldehydes in continuous flow | |
| Liu et al. | Copper-catalyzed synthesis of benzanilides from lignin model substrates 2-phenoxyacetophenones under an air atmosphere | |
| Jha et al. | Microwave assisted copper triflate-catalyzed rapid hydration of aryl acetylenes | |
| Kothandaraman et al. | Gold-and silver-catalyzed allylic alkylation of 1, 3-dicarbonyl compounds with allylic alcohols | |
| Kalla et al. | Tungstosulfonic acid as an efficient solid acid catalyst for acylal synthesis for the protection of the aldehydic carbonyl group | |
| Saulnier et al. | Brønsted Acid Promoted Cyclization of Cross‐Conjugated Enynones into Dihydropyran‐4‐ones | |
| KR101730867B1 (en) | Direct Oxidative Arylation of C(sp3)-H Bonds Adjacent to Oxygen of Ethers and Alcohols | |
| Samser et al. | Palladium mediated one-pot synthesis of 3-aryl-cyclohexenones and 1, 5-diketones from allyl alcohols and aryl ketones | |
| Ando et al. | Methylenation for Aldehydes and Ketones Using 1-Methylbenzimidazol-2-yl Methyl Sulfone | |
| Queensen et al. | Ferrocenium hexafluorophosphate as an inexpensive, mild catalyst for the etherification of propargylic alcohols | |
| El Ali et al. | Rh (I) or Rh (III) supported on MCM-41-catalyzed selective hydroformylation–acetalization of aryl alkenes: Effect of the additives | |
| Lebargy et al. | Radical Allylation: E-Selective Radical Conjugate Addition–Elimination Reaction from Morita–Baylis–Hillman Adducts | |
| Roselli et al. | Gold (i)-catalyzed addition of aldehydes to cyclopropylidene bearing 6-aryl-1, 5-enynes | |
| Titanyuk et al. | Trifluoromethylated cyclopropanes and epoxides from CuI-mediated transformations of α-trifluoromethyl-diazophosphonate | |
| Francesco et al. | Simple salts of abundant metals (Fe, Bi, and Ti) supported on montmorillonite as efficient and recyclable catalysts for regioselective intramolecular and intermolecular hydroalkoxylation reactions of double bonds and tandem processes | |
| Genin et al. | Gold-catalyzed hydroxy-and alkoxycyclization of functionalized enynes | |
| Siah et al. | Gold (I)-catalysed tandem cyclization of propargyl acetals and alkynes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant |