WO2011041529A2

WO2011041529A2 - Tri-2-naphthylamines

Info

Publication number: WO2011041529A2
Application number: PCT/US2010/050886
Authority: WO
Inventors: Carl E. Wagner
Original assignee: Arizona Board Of Regents Acting For And On Behalf Of Arizona State University
Priority date: 2009-10-01
Filing date: 2010-09-30
Publication date: 2011-04-07
Also published as: WO2011041529A3

Abstract

The invention relates to tri-2-naphthylamines that can be useful in a variety of optical devices as hole-transport materials. For example, the tri-2-naphthylamines can be useful as hole-transport materials in organic light emitting diodes.

Description

TRI-2-NAPHTHYL AMINES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Application No. 61/247,784, filed October 1, 2009, the entire contents of which are incorporated herein by reference.

ACKNOWLEDGEMENT

[0002] This invention was made with government support under Grant no. CHE-0741978 awarded by the National Science Foundation (NSF). The United States government has certain rights in the invention.

BACKGROUND

[0003] Materials for use in optical devices can be limited by instability and poor performance. Many materials for use in optical devices can also be difficult to process. Thus, there exists a need for improved materials for use in optical devices. This need and other needs are satisfied by the present invention.

SUMMARY

[0004] In accordance with the purpose(s) of the invention, as embodied and broadly described herein, this disclosure, in one aspect, relates to tri-2-naphthylamines. The tri-2- naphthylamines can be useful, inter alia, as hole transport materials for optical devices, such as organic light-emitting diodes (OLED)s.

[0005] In one aspect, the disclosed compounds are represented by the formula:

wherein R¹ is

a. hydrogen, b. NR², wherein R² is substituted or unsubstituted aryl, or c. OR , wherein R is hydrogen, substituted or unsubstituted -C₄ alkyl, or a protecting group.

[0006] Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE FIGURES

[0007] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects and together with the description serve to explain the principles of the invention.

[0008] FIG. 1 is an image of an X-ray crystal structure of tri-2-naphythylamine.

[0009] FIG. 2 is an image of an X-ray crystal structure of tris(2-tert-butyldimethylsilyloxy- naphthalen-6- yl)amine.

[0010] FIG. 3 contains color photographs showing fluorescence of a DCM solution of tris(2-methoxy-naphthalen-6-yl)amine (6), 16 mg/100 mL, as well as the solid state fluorescence of a sample of tris(2-methoxy-naphthalen-6-yl)amine, excited at 365 nm.

[0011] FIG. 4 is a plot of a UV-vis spectrum and emission spectra of tri-2-naphythylamine.

[0012] FIG. 5 is a plot of fluorescence emission spectra for tri-2-naphythylamine(5), tris(2- methoxy-naphthalen-6-yl)amine (6), tris(2-tert-butyldimethylsilyloxy-naphthalen-6- yl)amine (7), tris(2-hydroxy-naphthalen-6-yl)amine (8), and tris(2-acetoxy-naphthalen-6- yl)amin (9). The fluorescence spectra were taken with excitation at 380 nm DCM except tris(2-hydroxy-naphthalen-6-yl)amine (8) was taken in DMSO. Maxima at 426, 433, 443, 445, 456 nm, respectively. Fluorescence quantum yields (QY) were determined by the comparative method with cumarin 343 as the standard (φ = 0.63 in ethanol; see G.A.

Reynolds and K.H. Drexhage, Optics Comm., 13, 222-225, 1975). [0013] FIG. 6 is a plot of an absorbance spectrum of tri-2-naphythylamine(5).

[0014] FIG. 7 is a plot of an absorbance spectrum of tris(2-methoxy-naphthalen-6-yl)amine (6).

[0015] FIG. 8 is a plot of an absorbance spectrum of tris(2-tert-butyldimethylsilyloxy- naphthalen-6- yl)amine (7).

[0016] FIG. 9 is a plot of an absorbance spectrum of tris(2-hydroxy-naphthalen-6-yl)amine

(8) .

[0017] FIG. 10 is a plot of an absorbance spectrum of tris(2-acetoxy-naphthalen-6-yl)amin

(9) .

[0018] FIG. 11 is a plot of a cyclic voltammagram of tri-2-naphythylamine(5).

[0019] FIG. 12 is a plot of a cyclic voltammagram of tris(2-methoxy-naphthalen-6-yl)amine (6).

[0020] FIG. 13 is a plot of a cyclic voltammagram of tris(2-tert-butyldimethylsilyloxy- naphthalen-6- yl)amine (7).

[0021] FIG. 14 is a plot of a cyclic voltammagram of tris(2-hydroxy-naphthalen-6-yl)amine

(8) .

[0022] FIG. 15 is a plot of a cyclic voltammagram of tris(2-acetoxy-naphthalen-6-yl)amin

(9) ·

[0023] FIG. 16 is a plot of an absorbance spectrum of N²,N²-bis(6- (diphenylamino)naphthalen-2-yl)-N6,N6-diphenylnaphthalene-2,6-diamine.

[0024] FIG. 17 is a plot of an absorbance spectrum of N²,N²-bis(2-(N-(4-methoxyphenyl)-

N-phenylamino)naphthalene-6-yl)-N6-(4-methoxyphenyl)-N6-phenylnaphthalene-2,6- diamine.

[0025] FIG. 18 is a plot of a cyclic voltammagram of N²,N²-bis(6- (diphenylamino)naphthalen-2-yl)-N6,N6-diphenylnaphthalene-2,6-diamine. [0026] FIG. 19 is a plot of a cyclic voltammagram of N²,N²-bis(2-(N-(4-methoxyphenyl)-

N-phenylamino)naphmalene-6-yl)-N6-(4-methoxyphenyl)-N6-phenylriaphthalene-2,6- diamine.

DETAILED DESCRIPTION

[0027] The present invention can be understood more readily by reference to the following detailed description of the invention and the Examples included therein.

[0028] Before the present compounds, compositions, articles, systems, devices, and/or methods are disclosed and described, it is to be understood that they are not limited to specific synthetic methods unless otherwise specified, or to particular reagents unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, example methods and materials are now described.

[0029] As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a naphthylamine" includes mixtures of two or more naphthylamines.

[0030] Ranges can be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed. [0031] As used herein, the terms "optional" or "optionally" means that the subsequently described event or circumstance can or can not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0032] The compounds have the followin general formula:

wherein R is

a. hydrogen,

b. R , wherein R is substituted or unsubstituted aryl, or

c. OR , wherein R is hydrogen, substituted or unsubstituted C1-C4 alkyl, or a protecting group.

[0033] A number of compounds are described in the specification and examples herein. This disclosure is intended to include each of the steps, compounds, residues, and/or derivatives of these recited items individually and in various combinations.

[0034] The substituted Q-C4 alkyl substituent can be any branched or unbranched d-C₄ group. Examples include without limitation substituted or unsubstituted methyl, ethyl, propyl, isopropyl, or butyl. The Cj-C₄ alkyl group can be substituted with any appropriate substituent such as halide, hydroxyl, thiol, cyano, among others.

[0035] The protecting group can be any suitable protecting group. Examples include without limitation tert-butyl dimethylsulfoxide, and acetate.

[0036] In one aspect, R¹ is

a. hydrogen,

b. OMe,

c. OTBDMS,

d. OH,

e. OAc, or

f. NPh₂. [0037] Specific non-limiting examples of the compounds include:

[0038] The compounds can be made according to Scheme 1. Scheme 1

wherein X is halogen.

[0039] The napthyl-based halide is added to O-benzylhydroxylamine in excess, for example, about four equivalents. The catalyst is preferably Pd(OAc)₂ and tri-tert- butylphosphonium tetrafluoroborate and the base can be any suitable base such as NaOtBu. The catalyst can be used in any appropriate amount, for example, from about 2 to 10 mol %, relative to O-benzylhydroxylamine. The base is typically added in excess, for example 2 to 4 times excess relative to O-benzylhydroxylamine. Preferably, the napthyl-based halide is a napthyl-based bromide. The reaction can be carried out in a suitable solvent, such as toluene. Typically, the reaction mixture will be heated to reflux until the reaction is determined complete. After cooling to room temperature, the reaction mixture can be quenched with dilute acid, such as 1M HC1. The desired compound can be separated from byproducts or starting materials using column chromatography.

[0040] The compounds can be crystallized using methods known in the art. Crystal structures for two exemplary compounds are shown in FIGs. 1 and 2.

[0041] With reference to FIGs. 3-6, the compounds are fluorescent in both solution and in the solid-state. FIG. 3, for example, contains photographs showing fluorescence of tris(2- methoxy-naphthalen-6-yl)amine (6), excited at 365 nm. FIG. 4 shows a plot of a UV-vis spectrum and emission spectra of tri-2-naphythylamine. FIG. 5 shows further plots of fluorescence emission spectra for exemplary compounds. Optical data are summarized in

Table 1.

[0042] The compounds exhibit a reversible first oxidation as determined by cyclic voltammetry and at least one irreversible second oxidation. Cyclic voltammagrams for exemplary compounds are shown in FIGS. 11-15. Cyclic voltammetry data are summarized in Table 1. It will be appared that the addition of electron donating oxygen atoms in tris(2- methoxy-naphthalen-6-yl)amine and tris(2-tert-butyldimethylsilyloxy-naphthalen-6- yl)amine lowers the potential for the first oxidation, relative to tri-2-naphythylamine.

However, this property can be tuned by the addition of electron withdrawing acetyl groups to the oxygen, as the first oxidation potential for tris(2-acetoxy-naphthalen-6-yl)amine is higher than tri-2-naphythylamine.

[0043] Table 1. Optical and cyclic voltammetry data for exemplary compounds.

Compound ^max Abs ε (M^{' 1}) ^max Em Φ E^b (V)^a

(nm) (nm)

tri-2-naphythylamine (5) 284 30,420 425 0.16 0.89

322 27,404 (78)

350 18,212 1.29*

(diphenylamino)naphthalen- 313 25,107 0.82

2-yl)-N⁶,N⁶- 350 36,238 1.13^b diphenylnaphthalene-2,6- 389 20,661

diamine

N ,N -bis(2-(N-(4- 278 55,558 278 0.19 0.57 methoxyphenyl)-N- 353 54,024 0.76 phenylamino)naphthalene- 394 28,528 0.94

6-yl)-N⁶-(4- 1.09* methoxyphenyFj-N⁶- 1.36* phenylnaphthalene-2,6- diamine

aVersus SCE. * Indicates irreversible oxidation whose E_ox is E_p. The peak-to-peak separation (mV) is listed in parentheses for redox processes exhibiting reversible electrode kinetics.

[0044] The compounds are useful, inter alia, as hole-transporting materials for organic light-emitting diodes (OLEDs). Examples

[0045] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and/or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric.

[0046] 1H NMR spectra were acquired at 400 MHz on a Bruker Avance ΙΠ spectrometer. Chemical shifts (δ) are listed in ppm against an internal reference. Coupling constants (J) are reported in Hz, and the abbreviations for splitting include: s, single; d, doublet; t, triplet; q, quartet; p, pentet; m, multiplet; br, broad. ¹³C NMR spectra were acquired on a Bruker instrument at 100.6 MHz. Chemical shifts (5) are listed in ppm against solvent carbon peaks as an internal reference. High resolution mass spectra were recorded using either a JEOL GCmate(2004), a JEOL LCmate(2002) high resolution mass spectrometer or an ABI Mariner (1999) ESI-TOF mass spectrometer. Melting points were assayed on a Thomas Hoover capillary melting point apparatus.

[0047] Tetrahydrofuran, methylene chloride, diethyl ether, and benzene were dried by filtration through alumina according to the procedure described in Pangbora, A. B.;

Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.; Timmers, F. J. Organometallics 1996, 15, 1518. All other solvents were distilled from Ca¾ prior to use. Removal of volatile solvents transpired under reduced pressure using a Buchi rotary evaporator and is referred to as removing solvents in vacuo. Thin layer chromatography was conducted on precoated (0.25 mm thickness) silica gel plates with 60F-254 indicator (Merck). Column chromatography was conducted using 230-400 mesh silica gel (E. Merck reagent silica gel 60).

[0048] Absorption spectra were measured on a Shimadzu UV-3101PC UV-vis-NTR spectrometer. Absorption spectra for the compounds were taken in dichloromethane, whereas the spectrum for tris(2-hydroxy-naphthalen-6-yl)amine was taken in

dimethylsulfoxide. Steadystate fluorescence spectra were measured using a Photon

Technology International MP-1 spectrometer and corrected for detection system response. Excitation was provided by a 75 W xenon-arc lamp and single grating monochromator. Fluorescence was detected 90° to the excitation beam via a single grating monochromator and an R928 photomultipher tube having S-20 spectral response and operating in the single photon counting mode.

[0049] Cyclic voltammetry of the compounds shown was performed with a CHI 650C potentiostat (CH Instruments) using a glassy carbon disk (3mm) working electrode, a Pt gauze counter electrode, and a silver wire pseudo-reference electrode in a conventional three-electrode cell. These measurements were carried out in anhydrous dichloromethane (freshly distilled from calcium hydride) except for tris(2-hydroxy-naphthalen-6-yl)amine, which was carried out in acetonitrile, deoxygenated by bubbling with argon, with 0.10 M tetrabutylammonium hexafluorophosphate as the supporting electrolyte. The working electrode was cleaned between experiments by polishing with a 0.05 μ,τη alumina slurry, followed by solvent rinses. The concentration of the electroactive compound was maintained between 1.9 x 10^"4 M and 2.0 x 10^"4 M. After each voltammetric experiment, ferrocene was added to the solution, and the potential axis was calibrated against the formal potential of the ferrocenium/ferrocene redox couple (taken as 0.45 V vs SCE in

dichloromethane). The data presented in Table 1 is for voltammograms recorded at 35, 50, and 100 mV s^"1.

Tri-2-Naphythylamine

Scheme 2

[0050] With reference to Scheme 2, a 100 mL round bottom flask was charged with Pd(oAc)₂ (5.4 mg, 0.024 mmols), HPtBu₃ BF₄, (9.0 mg, 0.031 mmols), and NaOtBu (0.241 g, 2.51 mmols) all suspended in toluene (5.0 mL). Next, hydroxylamine O-benzyl ether (0.06 mL, 0.6 mmol) and 2-bromo naphthalene (0.417g, 2.0 mmols) were added to the reaction flask. The reaction was then heated (120-121 °C) and allowed to reflux for 18 hours in an oil bath and then set to cool at room temperature followed by quenching with addition of 1M HC1 (6 mL, 6 mmol). The aqueous layer was extracted with CH₂C1₂ (2 x 20 ml). The organic layer was combined and dried with sodium sulfate. The product was then filtered under high vacuum and reduced pressure to give a brown solid which was purified by column chromatography (Si0₂, ethyl acetate :hexanes 20:80) respectively to give tri-2- naphythylamine as an off-white powder: 0.0838 g (37%) m.p. 230.3 - 238.6 °C; 1H NMR (400 MHz, CDC1₃) δ 7.81-7.76 (m, 6H), 7.60 -7.58 (m, 3H), 7.52 (d, J = 2 Hz, 3H), 7.43- 7.37 (m, 9H); ¹³C NMR (100 MHz, CDC1₃) δ 145.4, 134.4, 130.3, 129.0, 127.6, 127.0, 126.3, 124.7, 124.6, 120.8. LCMS (M+H)+ Calc'd for C₃₀H₂₂N 396.1752, found 396.1753.

Tris(2-methoxy-naphthalen-6-yl)amine

Scheme 3

[0051] With reference to Scheme 3, a 100 mL round bottom flask was charged with

Pd(oAc)2 (0.0061 g, 0.027 mmols), HPtBu₃ BF₄ (0.0104 g, 0.0358 mmols) and NaOtBu (0.244 g, 2.5 mmols), all suspended in toluene (5 mL). Next, hydroxylamine Obenzyl ether (0.06 mL, 0.6 mmol) and 2-bromo-6-methoxynaphthalene (0.476 g, 2.0 mmols) were added to the reaction flask. The reaction was then heated (120-121 °C) and allowed to reflux for 18 hours in an oil bath, and then set to cool at room temperature followed by quenching with addition of 1M HC1 (6 mL, 6 mmols). The aqueous layer was separated by several extractions with CH₂C1₂ (2 x 20 ml). The organic layer was combined and dried with sodium sulfate. The product was then filtered under high vacuum and reduced pressure to give a brown solid which was purified by column chromatography (Si0₂, ethyl

acetate:hexanes 20:80) respectively to give Tris(2-methoxy-naphthalen-6-yl)amine as yellow crystals: 0.0756 g (27%) m.p. 257.3- 258.7 °C; 1H NMR (400 MHz, CDC1₃) δ 7.65 (d, J = 8.8 Hz, 3H), 7.49 (d, J = 9.2 Hz, 3H), 7.43 (d, J = 1.6 Hz, 3H), 7.33 (dd, J = 8.8, 2.4 Hz, 3H), 7.11 (d, J = 2.8 Hz, 3H), 7.08 (dd, J = 8.8, 2.4 Hz, 3H), 3.92 (s, 9H); ¹³C NMR (100 MHz, CDC1₃) δ 156.9, 143.9, 131.1, 129.8, 128.5, 127.7, 125.2, 120.6, 118.9, 105.9, 55.4. LCMS (M+H)+ calc'd for C₃₃H₂₈N0₃ 486.2069, found 486.2072.

Tris(2-tert-butyIdimethylsilyloxy-naphthalen-6- yl)amine

Scheme 4

2-Bromo-6-tert- but ldimethy!silyloxy-

[0052] With reference to Scheme 4, a 100 mL round bottom flask was charged with Pd(oAc)₂ (0.012 g, 0.053 mmols), HPtBu₃ BF₄ (0.020 g, 0.069 mmols) and NaOtBu (0.488 g, 5.08 mmols), all suspended in toluene (5 mL). Next, hydroxylamine O-benzyl ether (0.12 mL, 1.2 mmol) and 2-bromo-6-tert-butyldimethylsilyloxynaphthalene (1.35 g, 4.00 mmols) were added to the reaction flask. The reaction was then heated (120-121 °C) and allowed to reflux for 18 hours in an oil bath, and then set to cool at room temperature followed by quenching with addition of 1M HC1 (12 mL, 12 mmols). The aqueous layer was separated by several extractions with EtOAc (2 x 40 ml). The organic layer was combined and dried with sodium sulfate. The product was then filtered under high vacuum and reduced pressure to give a brown solid which was purified by column chromatography (Si0₂, ethyl acetate:hexanes 20:80) respectively to give tris(2-tert-butyldimethylsilyloxy-naphthalen-6- yl)amine as yellow crystals: 0.403 g (42%) m.p. 207-216 °C; 1H NMR (400 MHz, CDC1₃) δ 7.60 (d, J = 9.2 Hz, 3H), 7.48 (d, J = 8.8 Hz, 3H), 7.44 (d, J = 2.0 Hz, 3H), 7.33 (dd, J = 8.8, 2.0 Hz, 3H), 7.16 (d, J = 2.4 Hz, 3H), 7.01 (dd, J = 8.8, 2.4 Hz, 3H), 1.04 (s, 27H), 0.27 (s, 18H); ¹³C NMR (100 MHz, CDC1₃) δ 152.6, 143.9, 131.2, 130.1, 228.3, 127.6, 125.1, 122.3, 120.5, 114.9, 77.3, 77.0, 76.7, 25.7, 18.3. LCMS (M+H)+ calc'd for C^H^NOaSis 786.4194, found 786.4201.

Scheme 5

[0053] With reference to Scheme 5, for the synthesis of 2-Bromo-6-tert- butyldimethylsilyloxy-naphthalene, the method described in Medieta, M. A. E. P. -B.; Negri, M.; Jagusch, C; Hille, U. E.; Muller-Vieira, U.; Schmidt, D.; Hansen, K.; Hartmann, R. W. Bioorg. & Med. Chem. Lett.2008, 18, 267 was followed. To a 500 mL round bottom flask charged with 6-bromo-2-naphthol (10.0 g, 44.8 mmols) and imidazole (3.40 g, 49.9 mmols) dissolved in DCM (100 mL) was added a solution of tertbutyldimethylsilylchloride (7.42 g, 49.2 mmols) in DCM (50 mL). The reaction mixture was stirred 17h, poured into water and extracted with EtOAc twice (100 mL). The combined organic extracts were dried over sodium sulfate, concentrated in vacuo and purified by column chromatography (Si0₂, hexanes) to give 2-Bromo-6-tert-butyldimethylsilyloxy-naphthalene as off-white crystals: 14.32 g (94%) m.p. 64-66 °C; 1H NMR (400 MHz, CDC1₃) δ 7.92 (d, J = 0.8 Hz, 1H), 7.63 (d, J = 8.8 Hz, 1H), 7.56 (d, J = 8.8 Hz, lH), 7.48 (dd, J = 8.8, 2.0 Hz, 1H), 7.16 (s, 1H), 7.09 (dd, J = 8.8, 2.4 Hz, 1H), 1.02 (s, 9H), 0.25 (s, 6H); ¹³C NMR (100 MHz, CDC1₃) δ 153.8, 133.0, 130.3, 129.6, 129.4, 128.4, 128.3, 123.1, 117.3, 114.9, 25.7, 18.2, -4.3. LCMS (M+H)+ calc'd for C16H220BrSi 337.0623, found 337.0584.

Tris(2-hydroxy-naphthalen-6-yl)amine

[0054] To a 20 dram screw-cap vial containing tris(2-tert-butyldimethylsilyloxy- naphthalen-6- yl)amine (0.7209 g, 0.917 mmols) dissolved in THF (2.0 mL) was added a solution of TBAF-3H₂0 (0.9123 g, 2.89 mmols) in THF (2.0 mL) and an additional portion of THF (2.0 mL) was added to the reaction at room temperature. The reaction was stirred overnight at room temperature, and this was followed by the addition of 1M HCl (3 mL, 3.0 mmols). The mixture was extracted twice with EtOAC (40 mL), and the organic layers were dried over sodium sulfate, filtered, concentrated in vacuo and purified by column chromatography (Si02, ethyl acetate:hexanes 20:80) respectively to give tris(2-hydroxy- naphthalen-6-yl)amine as a green solid: 0.2589 g (63%) m.p. 268-272 °C; 1H NMR (400 MHz, D₆-DMSO) δ 9.58 (s, 3H), 7.62 (d, J = 8.8, 3H), 7.53 (d, J = 9.2 Hz, 3H), 7.32 (d, J = 2 Hz, 3H), 7.18 (dd, J = 8.8, 2.4 Hz, 3H>, 7.07 (d, J = 2.0 Hz, 3H), 6.98 (dd, J = 8.8, 2.4 Hz, 3H); ¹³C NMR (100 MHz, D₆-DMSO) 5 154.5, 142.7, 131.1, 128.5, 128.3, 127.3, 124.6, 120.1, 118.8, 108.8. LCMS (M+H)+ calc'd for C₃₀H₂₂NO₃ 444.1600, found 444.1598.

Tris(2-acetoxy-naphthalen-6-yI)amine

[0055] To a 250 mL round bottom flask containing 8 (0.5072 g, 1.14 mmol) and a stir bar was added acetic anhydride (24 mL, 250 mmol) and a water condenser was attached. The solution was heated at reflux in an oil bath (150-165 °C) with stirring for 1 h. After cooling the reaction to room temperature, the reaction was poured into water (50 mL) and extracted twice with EtOAc (40 mL). The organic extracts were dried over sodium sulfate, concentrated in vacuo and purified by column chromatography (Si0₂, ethyl acetate:hexanes 20:80 to 1:1 EtOAc:hexanes) respectively to give tris(2-acetoxy-naphthalen-6-yl)amine as yellow crystals: 0.64 g (98%) m.p. 158-166 °C; 1H NMR (400 MHz, CDC1₃) δ 7.72 (d, J = 8.8 Hz, 3H), 7.59 (d, J = 9.2 Hz, 3H), 7.51 (d, J = 2.4 Hz, 3H), 7.49 (d, J = 2.4 Hz, 3H), 7.36 (dd, J = 8.8, 2.0 Hz, 3H), 7.16 (dd, J = 8.8, 2.4 Hz, 3H), 2.36 (s, 9H); ¹³C NMR (100 MHz, CDC1₃) δ 169.3, 147.6, 145.2, 132.5, 130.5, 128.9, 128.5, 125.3, 121.7, 120.8, 118.5, 21.2. LCMS (M+H)+ calc'd for C₃₆H₂₈N0₆ 570.1917, found 570.1925.

6-bromo-N-phenyInaphthaIen-2-amine

[0056] The method of Reinhardt and co-workers was followed. A mixture of 2-bromo-6- naphthol (10.93 g, 49.0 mmol), aniline (17.0 mL, 187 mmol), ?-toluenesulfonic acid monohydrate (1.81 g, 9.52 mmol) in j9-xylene (17 mL) in a 250 mL round bottom flask fitted with a Dean-Stark trap and water-coil condenser was heated under nitrogen in an oil bath to 175 °C, at which point a portion of the /^-xylene and water (~9 mL) was distilled off to raise the reflux temperature to 190 °C. The reaction was stirred at 190 °C for 5 hours, then cooled to 55 °C at which point anhydrous sodium acetate (2.47 g, 30.0 mmol) and ethanol (66 mL) were added and the solution was brought to reflux and stirred for 15 minutes. The solution was then cooled in an ice-water bath with stirring, and the resulting precipitate was filtered, washed with cold ethanol and dried under air to give a crude, light brown product (6.57 g). The crude product was added to warm water (100 mL) and the resulting slurry was filtered and dried to give the title compound as a white powder (3.92 g, 26.8%) m.p. (lit. m.p. ); 1H NMR (400 MHz, CDC1₃) δ 7.89 (d, J= 1.6 Hz, 1H), 7.64 (d, J = 8.8 Hz, 1H), 7.50 (d, J= 8.8 Hz), 7.46 (dd, J= 8.8, 1.6 Hz, 1H), 7.38 (d, J= 2.4 Hz, 1H), 7.34 (t, J= 7.6 Hz, 2H), 7.24 (dd, J= 8.8, 2.4, 1H), 7.19 (d, J= 1.6 Hz, 1H), 7.17 (d, J= 1.6 Hz, 1H), 7.03 (t, J= 7.6 Hz, 1H), 5.59 (br s, 1H); ¹³C NMR (100 MHz, CDC1₃) 5 142.2, 141.3, 133.0, 130.0, 129.7, 129.6, 129.5, 128.3, 128.0, 121.9, 120.6, 118.7, 116.7, 110.7; GCMS (M)⁺ Calc'd for C₁₆H₁₂NBr 297.0153, found 297.0144.

6-bromo-/V-phenylnaphthalen- 2-amine

6-bromo-NJV-diphenylnaphthalen-2-amine

[0057] Since the method of Reinhardt and co-workers gave spurious yields in our hands, the method of Wang and co-workers to make N-(4-bromophenyl)-4-methoxy-N- phenylbenzenamine was adapted and used. To a 100 mL round bottom flask was added 6- bromo-N-phenylnaphthalen-2-amine (3.70 g, 12.4 mmols), copper (I) chloride (0.134 g, 1.35 mmols), 1,10-phenanthroline monohydrate (0.267 g, 1.35 mmols), powdered potassium hydroxide (7.51 g, 134 mmols), iodobenzene (1.84 mL, 16.4 mmols) and toluene (30.5 mL). A stir bar was added, the reaction flask was fitted with a water cooled condenser, and the apparatus was evacuated and backfilled with nitrogen. The reaction was then heated to reflux in an oil bath at 125 °C with stirring for 36 hours. The reaction solution was cooled, and TLC indicated complete conversion of the limiting starting material. The reaction was poured into water and extracted with CH₂CI₂ (40 mL, thrice). The organic extracts were washed with water followed by brine and then dried over sodium sulfate, filtered and concentrated to give crude product. The crude product was

chromatographed on silica (150 mL) in ethylacetate:hexanes (0.5% to 1.0%) to give the title compound as a pure, white powder (3.145 g, 67%) m.p. 128.4-128.8 °C (lit. 135.8-137.4 °C); 1H NMR (400 MHz, CDC1₃) δ 7.89 (s, 1H), 7.60 (d, J= 8.8 Hz, 1H), 7.44 (d, J= 1.6 Hz, 2H), 7.35 (d, J= 2.4 Hz, 1H), 7.31 (t, J= 2.4 Hz, 1H), 7.29 (d, J= 0.8 Hz, 3H), 7.26 (t, J= 2.4 Hz, 1H), 7.15 (d, J= 1.2 Hz, 2H), 7.13 (d, J= 1.2 Hz, 2H), 7.09 (t, J= 7.6 Hz, 2H); ¹³C NMR (100 MHz, CDC1₃) δ 147.4, 145.9, 132.8, 130.7, 129.5, 129.3, 128.4, 127.8, 124.9, 124.6, 123.2, 119.1, 117.8; GCMS (M)⁺ Calc'd for C₂₂H₁₆NBr 373.0466, found 373.0470.

6-bromo-/V,/V-diphenyl- naphthalen-2-amine

6-bromo-iV-(4-methoxyphenyl)-N-phenylnaphthalen-2-aminE

[0058] The method of Wang and co-workers was adapted and used. To a 100 mL round bottom flask was added 6-bromo-N-phenylnaphthalen-2-amine (2.98 g, 10.0 mmols), copper (I) chloride (0.101 g, 1.02 mmols), 1,10-phenanthroline monohydrate (0.20 g, 1.01 mmols), powdered potassium hydroxide (5.65 g, 101 mmols), 4-methoxy-l-iodobenzene (2.88 g, 12.3 mmols) and toluene (22.5 mL). A stir bar was added, the reaction flask was fitted with a water cooled condenser, and the apparatus was evacuated and backfilled with nitrogen. The reaction was then heated to reflux in an oil bath at 125 °C with stirring for 36 hours. The reaction solution was cooled, and TLC indicated complete conversion of the limiting starting material. The reaction was poured into water and extracted with C¾C1₂ (40 mL, thrice). The organic extracts were washed with water followed by brine and then dried over sodium sulfate, filtered and concentrated to give crude product. The crude product was dry-loaded onto a column of silica (250 mL) and chromatographed in ethylacetate:hexanes 1 :20 to give the pure title compound (3.53 g, 87%) as a light yellow powder, m.p. 160-162 °C; 1H NMR (400 MHz, CDC1₃) δ 7.89 (s, 1H), 7.60 (d, J= 10 Hz, 1H), 7.44 (d, J= 1.6 Hz, 2H), 7.29 (t, J= 4.8 Hz, 4H), 7.13 (d, J= 8.8 Hz, 2H), 7.12 (dd, J - 6.4, 0.8 Hz, 2H), 7.04 (t, J= 7.6 Hz, 1H), 6.91 (dd, J= 6.8, 2.4 Hz, 2H), 3.85 (s, 3H); ¹³C NMR (100 MHz, CDC1₃) 6 156.4, 147.7, 146.2, 140.3, 132.8, 130.3, 129.4, 129.2, 128.3, 127.7, 127.4, 124.1, 123.5, 122.6, 117.4, Π7.3, 114.8, 55.4; GCMS (M)⁺ Calc'd for C₂₃H₁₈NOBr 403.0572, found 403.0565.

OCH₃

6-bromo-/V-(4-methoxyprienyl)- N-phenylnaphthalen-2-amine

N²,A^-bis(2-(diphenylamino)naphthaIene-6-yl)-N^tf,iV⁵- dipheylnaphthalene-2,6- diamine

[0059] The method of Bedford and Betham was followed. A 100 mL round bottom flask was charged with Pd(oAc)₂ (6.1 mg, 0.027 mmols), HP^lBu₃ BF₄, (10.4 mg, 0.036 mmols), and NaO^lBu (0.241 g, 2.51 mmols) all suspended in toluene (5.5 mL). Next, hydroxylamine O-benzyl ether (0.06 mL, 0.6 mmol) and 6-bromo-N,N-diphenylnaphthalen-2-amine (0.7595 g, 2.00 mmols) were added to the reaction flask. The reaction was then heated (120-121 °C) and allowed to reflux for 18 hours in an oil bath and then set to cool at room temperature followed by quenching with addition of 1M HC1 (6 mL, 6 mmol). The heterogeneous solution was then filtered on medium porosity paper and washed with copious amounts of water and ethyl acetate to give the title compound as a bright canary yellow powder: 0.1659 g (30.8%) m.p. 310 - 311 °C; 1H NMR (400 MHz, C₆D₆) δ 7.55 (d, J= 2.0 Hz, 3H), 7.47 (d, J= 2.0 Hz, 3H), 7.28 (dd, J= 8.8, 2.0 Hz, 3H), 7.22 (d, J= 8.8 Hz, 3H), 7.18 (d, J - 6.0 Hz, 3H), 7.14 (d, J = 1.6 Hz, 6H), 7,12 (d, J = 1.2 Hz, 6H), 7.07 (d, J= 8.8 Hz, 6H), 7.05 (d, J = 3.2 Hz, 6H), 6.85 (t, J = 7.6 Hz, 6H); high resolution LCMS (M+H)⁺ Calc'd for C6₆H4₉N₄ 897.3957, found 897.3909.

W²,W²-bis(2-(diphenylamino)naphthalen-6-yl)-W

diphenylnaphthalene-2,6-diamine

A^r2^²-bis(2-( V-(4-methoxyphenyl)-iV-phenylamino)-naphthalen-6-yl)- N⁶-(4-methoxy- pheny^-iV^-phenylnaphthalene- _je-diamine

[0060] The method of Bedford and Betham was followed. A 100 mL round bottom flask was charged with Pd(oAc)₂ (6.7 mg, 0.029 mmols), HP^£Bu₃ BF₄, (11.4 mg, 0.039 mmols), and NaO'Bu (0.246 g, 2.56 mmols) all suspended in toluene (5.5 mL). Next, hydroxylamine O-benzyl ether (0.06 mL, 0.6 mmol) and 6-bromo-N-(4-methoxyphenyl)-N- phenylnaphthalen-2-amine (0.812 g, 2.01 mmols) were added to the reaction flask. The reaction was then heated (120-121 °C) and allowed to reflux for 18 hours in an oil bath and then set to cool at room temperature followed by quenching with addition of 1M HC1 (6 mL, 6 mmol). The aqueous layer was extracted with EtOAc (2 x 50 ml). The organic layers were combined, washed with water and brine, and dried over sodium sulfate. The product solution was then filtered, and concentrated under reduced pressure to give a crude oil which was purified by column chromatography (150 mL Si0₂, ethyl acetate :hexanes 1 :20) respectively to give the title compound as a yellow brown powder: 0.123 g (21.8%) m.p. 262 - 264 °C; 1H NMR (400 MHz, CDC1₃) δ 8.20 - 6.86 (m, 45H), 3.82 (s, 3H); high resolution LCMS (M+H)⁺ Calc'd for C₆₉H₅₅N₄0₃ 987.4274, found 987.4323.

V²,/V²-bis(2-(W-(4-methoxyphenyl)-/V-phenylamino)naphthalen-6-yl)- /\/⁶-(4-methoxyphenyl)-/\/⁶-phenylnaphthalene-2,6-diamine

[0061] The method of Bedford and Betham was followed. A 100 mL round bottom flask was charged with Pd(oAc)₂ (6.7 mg, 0.029 mmols), HP^lBu₃ BF₄, (11.4 mg, 0.039 mmols), and NaO^lBu (0.246 g, 2.56 mmols) all suspended in toluene (5.5 mL). Next, hydroxylamine 0-benzyl ether (0.06 mL, 0.6 mmol) and 6-bromo-N-(4-methoxyphenyl)-N- phenylnaphthalen-2-amine (0.812 g, 2.01 mmols) were added to the reaction flask. The reaction was then heated (120-121 °C) and allowed to reflux for 18 hours in an oil bath and then set to cool at room temperature followed by quenching with addition of 1M HC1 (6 mL, 6 mmol). The aqueous layer was extracted with EtOAc (2 x 50 ml). The organic layers were combined, washed with water and brine, and dried over sodium sulfate. The product solution was then filtered, and concentrated under reduced pressure to give a crude oil which was purified by column chromatography (150 mL Si0₂, ethyl acetate:hexanes 1 :20) respectively to give the title compound as a yellow brown powder: 0.123 g (21.8%) m.p. 262 - 264 °C; 1H NMR (400 MHz, CDC1₃) δ 8.20 - 6.86 (m, 45H), 3.82 (s, 3H); high resolution LCMS (M+H)⁺ Calc'd for C₆₉H₅₅N₄0₃ 987.4274, found 987.4323. [0062] Other compounds that can be prepared in accordance with the various methods and compounds of this disclosure can comprise:

[0063] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.