A kind of aromatic boronic acid ester composite synthetic method
Technical field
The invention belongs to organic synthesis intermediate technical fields, and in particular to a kind of to utilize the fragrant boron of UV light-induced synthesis
The method of ester compound.
Background technology
Aromatic boronic acid ester composite is very important intermediate in organic synthesis, is widely used in the intersections such as suzuki idol
Connection reaction.The traditional preparation methods of aryl-boric acid ester are that Grignard Reagent or organolithium reagent are reacted with trialkylboron ester, through hydrolysis
Resterification.But this method has certain limitation, needs the condition of low temperature and stringent anhydrous and oxygen-free, and functional group tolerance is poor.
In recent years, the aromatic boronic acid ester composite synthetic method of document report has very much.Transition metal-catalyzed aryl halogenation
The coupling reaction of object and connection boric acid pinacol ester is to synthesize the most classical way of this kind of compound.This method biggest advantage
It is that applicability is very extensive, and easy to operate, is not required to stringent anhydrous and oxygen-free condition.But there are also shortcomings, such as your gold
Belong to the use of palladium catalyst and the residual of transition metal can not be avoided, this problem shows particularly in drug molecule synthesis
It is prominent.In addition, it is a kind of completely new using the direct boronation reaction of transition metal (rhodium or iridium catalyst) catalyzing aromatic hydrocarbon carbon-hydrogen link
Synthesizing aryl boric acid ester compound method.The features such as such reaction embodies Green Chemistry, Atom economy, the region choosing of reaction
Selecting property is mainly controlled by steric hindrance, obtains the boronation product based on meta position.However, such reaction or needs utilize expensive mistake
Cross metallic catalyst and the reaction condition of harshness.Recently, a kind of no metal of document report participates in, with benzene cheap and easy to get
One step of amine can synthesize aromatic boronic acid ester composite.The condition of the reaction is as mild as a dove, it might even be possible to be carried out under air conditions anti-
Should, and participated in without metal, in this way can be to avoid metal residual the problem of.Then, it is catalyzed aromatic diazo salt using organic photosensitizer
Boronation reaction can also synthesize such compound.However, aromatic diazo salt compound is not sufficiently stable, be not suitable for mass production, and not
It is easy to maintain.Although the mechanism of such reaction is also not very clear, it may be possible to experienced free radical mechanism.
It is contemplated that the aryl sulfonyl chloride in reaction system, connection boric acid pinacol ester occurs certainly under conditions of light-initiated
Aromatic boronic acid ester composite is built by base coupling reaction.The response strategy has certain challenge.So far, there has been no
Document report.
Invention content
The technical problems to be solved by the invention are:In view of the deficienciess of the prior art, provide a kind of at low cost, yield
The high method using free radical coupling reaction synthesis aromatic boronic acid ester composite.
Purpose to realize the present invention, is achieved using following technical scheme:A kind of aromatic boronic acid ester composite synthesis
Method,
Reaction equation is
Specifically comprise the following steps:
1. adding in acetonitrile, aryl sulfonyl chloride, connection boric acid pinacol ester and dipotassium hydrogen phosphate into reaction tube, reaction tube is tightened
Plug, with ultra violet lamp reaction tube, magnetic agitation is reacted 24 hours at room temperature;
2. treating after reaction, decompression boils off most of solvent, using volume ratio as 10:1~30:1 petroleum ether and acetic acid
Ethyl ester carries out remaining mixed liquor for leacheate column chromatography for separation purification to get product.
As preferred:Aryl sulfonyl chloride is coupled with connection boric acid pinacol ester free radical in reaction.
Compared with prior art, the beneficial effects of the invention are as follows:The present invention use aryl sulfonyl chloride cheap and easy to get for
Raw material can be efficiently synthesized a series of aromatic boronic acid ester composite through UV light-induced.The compound of the present invention can be used as
It organic synthesis intermediate and has a wide range of applications in numerous areas such as material, medicine, pesticides.The present invention passes through free radical idol
Connection reaction synthesis aromatic boronic acid ester composite.Compared with existing synthetic method, the method for the present invention operation is simple, raw materials used warp
It helps, be easy to get, yield is higher.
Specific embodiment
Embodiment 1:The synthesis of borate ester
Acetonitrile 2mL, benzene sulfonyl chloride (52.8mg, 0.3mmol), connection boric acid pinacol ester are added in into 25mL reaction tubes
(114.3mg, 0.45mmol), dipotassium hydrogen phosphate (104.4mg, 2.0eq.), with ultra violet lamp reaction tube, magnetic force at room temperature
It is stirred to react 24 hours.It treats after reaction, decompression boils off most of solvent, with petrol ether/ethyl acetate (30:1) it is elution
Liquid carries out remaining mixed liquor column chromatography for separation purification to get required product, for white solid, 39.8mg, yield 65%.
Its nuclear-magnetism modal data is as follows:
1H NMR(300MHz,CDCl3) δ=7.94~7.90 (m, 1H), 7.84 (d, J=6.0Hz, 1H), 7.64 (d, J=
6.0Hz, 1H), 7.50~7.28 (m, 2H), 1.37 (s, 12H)13C NMR(75MHz,CDCl3) δ=137.6,134.7,
131.2,127.7,127.1,83.8,24.9.
Embodiment 2:The synthesis of 4- methylphenylboronic acid esters
Acetonitrile 2mL, 4- toluene sulfonyl chloride (57.0mg, 0.3mmol), connection boric acid pinacol are added in into 25mL reaction tubes
Ester (114.3mg, 0.45mmol), dipotassium hydrogen phosphate (104.4mg, 2.0eq.), with ultra violet lamp reaction tube, magnetic at room temperature
Power is stirred to react 24 hours.It treats after reaction, decompression boils off most of solvent, with petrol ether/ethyl acetate (30:1) it is leaching
Washing lotion carries out remaining mixed liquor column chromatography for separation purification to get required product, for white solid, 44.5mg, yield 68%.
Its nuclear-magnetism modal data is as follows:
1H NMR(300MHz,CDCl3) δ=7.81 (d, J=9.0Hz, 2H), 7.27 (d, J=9.0Hz, 2H), 2.44 (s,
3H),1.41(s,12H).13C NMR(75MHz,CDCl3) δ=141.4,134.9,128.6,83.6,24.9,21.8.
Embodiment 3:The synthesis of 4- methoxyphenylboronic acid esters
Acetonitrile 2mL, 4- toluene sulfonyl chloride (61.8mg, 0.3mmol), connection boric acid pinacol are added in into 25mL reaction tubes
Ester (114.3mg, 0.45mmol), dipotassium hydrogen phosphate (104.4mg, 2.0eq.), with ultra violet lamp reaction tube, magnetic at room temperature
Power is stirred to react 24 hours.It treats after reaction, decompression boils off most of solvent, with petrol ether/ethyl acetate (20:1) it is leaching
Washing lotion carries out remaining mixed liquor column chromatography for separation purification to get required product, for white solid, 49.2mg, yield 70%.
Its nuclear-magnetism modal data is as follows:
1H NMR(300MHz,CDCl3) δ=7.81 (d, J=9.0Hz, 2H), 6.92 (d, J=9.0Hz, 2H), 3.83 (s,
3H),1.36(s,12H).13C NMR(75MHz,CDCl3) δ=162.2,136.5,113.3,83.5,55.0,24.9.
Embodiment 4:The synthesis of 4- nitrobenzene boronic acid esters
Acetonitrile 2mL, 4- toluene sulfonyl chloride (66.3mg, 0.3mmol), connection boric acid pinacol are added in into 25mL reaction tubes
Ester (114.3mg, 0.45mmol), dipotassium hydrogen phosphate (104.4mg, 2.0eq.), with ultra violet lamp reaction tube, magnetic at room temperature
Power is stirred to react 24 hours.It treats after reaction, decompression boils off most of solvent, with petrol ether/ethyl acetate (10:1) it is leaching
Washing lotion carries out remaining mixed liquor column chromatography for separation purification to get required product, for yellow solid, 58.3mg, yield 78%.
Its nuclear-magnetism modal data is as follows:
1H NMR(300MHz,CDCl3) δ=8.18 (d, J=9.0Hz, 2H), 7.95 (d, J=9.0Hz, 2H), 1.36 (s,
12H).13C NMR(75MHz,CDCl3) δ=149.8,135.6,122.3,84.6,24.8.MS (EI):249(25),234
(100),163(31),83(11).
Above-described embodiment is only more preferred embodiment, every using the method for the present invention or to carry out conventional being equal and replace
It changes, modify etc. and belonging to the scope of the present invention.