A Photocleavable Linker for the Chemoselective Functionalization of Biomaterials

Transcription

1 Electronic Supplementary Information A otocleavable Linker for the Chemoselective Functionalization of Biomaterials Liz Donovan and Paul A. De Bank* Department of armacy and armacology and Centre for Regenerative Medicine, University of Bath, Bath BA2 7AY, UK. * p.debank@bath.ac.uk; Fax: +44 (0) ; Tel: +44 (0) General Experimental All reagents were purchased from Sigma-Aldrich (Dorset, U.K.) and used without further purification unless otherwise specified. All reactions were carried out in freshly dried and distilled solvents under a dry nitrogen atmosphere apart from those involving aqueous solutions. MR spectra were recorded on Bruker Avance III 400 Mz or 500 Mz MR spectrometers. Data are expressed in parts per million downfield from SiMe 4 as an internal standard or relative to CCl. MR assignments were supported by - C and - MR 2D spectra and DEPT for compound 4-7 and caged aldehyde. J vales are given in z. IR spectra were measured on a Perkin Elmer Spectrum RXI FT-IR spectrophotometer and reported as cm -. Mass spectra were obtained using Bruker micrtf spectrometers in electrospray positive ion mode. Reaction Scheme 2 Br a) b) Br C 4 5 c) ' e) d) a) Bi(Tf), toluene, 80 C; b) Et 4 C, MeC, reflux; c) K, 2-methoxyethanol, reflux; d) - hydroxysuccinimide,, -diisopropylcarbodiimide, C 2 Cl 2, rt; e) 2 (C 2 C 2 ) (C 2 ) 2 2 (8), C 2 Cl 2 rt. Synthesis 4-(Dimethylamino)-2-(hydroxydiphenylmethyl)phenol (2) was prepared according to the synthetic route described by Wang et al.

2 4-Bromobutanal () DMS (0.50 ml, 6.44 mmol) in dichloromethane (4 ml) was added to oxalyl chloride (0.4 ml, 4.57 mmol) in dichloromethane (4 ml) at -78 C. After 5 minutes a solution of 4-bromo--butanol (0.68 g, 4.44 mmol) in dichloromethane (8 ml) was added to the mixture and after 0 minutes,,diisopropylethylamine (2.50 ml, 4. mmol) was added. The solution was stirred at -65 C for 5 minutes and for an additional 5 minutes at room temperature, poured into 0% citric acid and extracted with dichloromethane ( x 0 ml). The organic layer was washed with saturated ac (0 ml) and dried over MgS 4. The solution was evaporated to dryness and the residue purified by silica column chromatography (:4 dichloromethane/hexane) to yield compound (0.54 g, 80%) as a colourless oil; R f 0.45 (: dichloromethane/hexane); δ (400 Mz; CDCl ; Me 4 Si) (2, quintet, C 2 ), (2, m, C 2 ), (2, t, J = 6.0, C 2 ), 9.8 (, s, C). Spectroscopic data are consistent with those described in the literature. 2 2-(-Bromopropyl)-,-dimethyl-4,4-diphenyl-4-benzo[d][,]dioxin-6-amine (4) otolabile protecting group 2 (0.70 g, 2.20 mmol), 4-bromobutanal (.00 g, 6.60 mmol), Bismuth (III) trifluromethanesulfonate (0.05 g, 0.02 mmol), in toluene (8 ml) were heated at 80 ºC under nitrogen for 72 hr. The reaction was quenched with saturated aqueous sodium hydrogen carbonate solution (0 ml) and extracted with EtAc (2 x 20 ml). The organic extracts were combined and dried (MgS 4 ). The solution was evaporated to dryness and the residue purified by silica column chromatography (0.5:9.5 EtAc/hexane) to yield compound 4 as a colourless oil (0.80 g, 8%); R f 0.48 (0.5:9.5 EtAc/hexane); δ (400 Mz; CDCl ; Me 4 Si) (4, m, (C 2 ) 2 ), 2.7 (6, s, 2 x C ), (2, t, J 6.7, C 2 Br), (, t, J 4.7, C), (, d, J 5 2.6, Ar-), (, dd, J 8.9, J 5 2.6, Ar-), (, d, J 8.9, Ar-), (0, m, -); δ C (00 Mz; CDCl ; Me 4 Si) 26.8 (C 2 ), 2.9 (C 2 ),.4 (C 2 ), 4.5 (2 x C ), 84. (C), 9.9 (C), 4.5 (Ar-C), 4.7 (Ar-C), 7.2 (Ar-C), 25.2, 27., 27.7, 27.8, 27.9, 28.0, 29. (all -C), 44., 44.5, 44.6, 46.0 (ipso-c); v max /cm - 468, 47, 650, 50, 49; RMS (ESI): found M +, (C Br 2 requires ); m/z (ES) 452 (C Br 2, 45%), 02 (00), 289 (8). 4 Br MR in CDCl 2

3 4 Br C MR in CDCl 4-(6-(Dimethylamino)-4,4-diphenyl-4-benzo[d][,]dioxin-2-yl)butanenitrile (5) Bromide 4 (0.0 g, 0.29 mmol) and tetraethylammonium cyanide (Et 4 C) (0.067 g, mmol) were dissolved in MeC (5 ml). The solution was heated at reflux for 5.5 hr, cooled and reduced to dryness. The resultant orange residue was purified by silica column chromatography (2:8 EtAc/hexane) to yield compound 5 as a colourless oil (0. g, 96%) R f 0.5 (2: EtAc/hexane); δ (400 Mz; CDCl ; Me 4 Si) (4, m (C 2 ) 2 ), (2, t, J 7.0, C 2 C), 2.7 (6, s, 2 x C ), (, t, J 4.5, C), (, d, J 5.0, -), (, dd, J 9.0, J 5.0, -), (, d, J 9.0, - ), (0, m -); δ C (00 Mz; CDCl ; Me 4 Si) 7.4 (C 2 ), 20. (C 2 ),.5 (C 2 ), 4.8 (2 x C ), 85.0 (C), 94.2 (C), 4.9 (Ar-C), 7.7 (Ar-C), 9.0 (C), 25.7, 27.9, 28., 28.5, 28.5, 28.7, 44.7, 44.8, 45. (all Ar-C); v max /cm - 292, 62, 56, 446, 28; RMS (ESI): found M +, (C requires ); m/z (ES) 99 (C , 7%), 02 (00), 288 (55). 4-(6-(Dimethylamino)-4,4-diphenyl-4-benzo[d][,]dioxin-2-yl)butanoic acid (6) itrile 5 (0.0 g, 0.75 mmol), was dissolved in a saturated solution of K in 2-methoxy methanol (2 ml). The solution was heated at reflux for 8 hr, cooled and Cl (2 M) was added dropwise until the p was adjusted to 2. The solution was extracted with C 2 Cl 2 (2 x 20 ml), the organic extracts were combined, dried over MgS 4 and reduced to dryness to yield compound 6 as a brown oil (0.28 g, 89%); R f 0.2 (: EtAc/hexane); δ (400 Mz; CDCl ; Me 4 Si) (4, m (C 2 ) 2 ), (2, m, C 2 C), 2.7 (6, s, 2 x C ), (, t, J 4.6, C), (, br s, ), (, br s, -), (, m, -), (, m, -), (0, m -); δ C (00 Mz; CDCl ; Me 4 Si) 9.5 (C 2 ),.4 (C 2 ), 5. (C 2 ), 4.6 (2 x C ), 84.4 (C), 94.4 (C), 4.9 (Ar-C), 7.2 (Ar-C), 25.4 (C), 27., 27.7, 27.8, 27.9, 28.0, 29., 44., 46., 74.9 (C=); v max /cm - 074, 706, 565, 67; RMS (ESI): found M +, (C requires ); m/z (ES) 48 (C , 00%), 02 (67.9), 27 (7).

4 5 C MR in CDCl 5 C C MR in CDCl 4

5 6 MR in CDCl 6 C MR in CDCl 2,5-Dioxopyrrolidin--yl 4-(6-(dimethylamino)-4,4-diphenyl-4-benzo[d][,]dioxin-2-yl) butanoate (7) To a solution of acid 6 (0.20 g, mmol) and -hydroxysuccinimide (0.066 g mmol) in anhydrous C 2 Cl 2 (2 ml) was added, -diisopropylcarbodiimide (0.07 g, mmol) in anhydrous C 2 Cl 2 (2 ml). The solution was stirred for 72 hr at room temperature and quenched with brine. The aqueous layer was extracted with C 2 Cl 2 ( x 0 ml), the organic layers were combined and dried over MgS 4. The solution was evaporated to dryness and the residue purified by silica column chromatography (: EtAc/hexane) to yield compound 7 as a yellow oil (0.24 g, 95%); R f 0.60 (: EtAc/hexane); δ (400 Mz; CDCl ; Me 4 Si) (4, m, (C 2 ) 2 ), (2, m, C 2 ), 2.7 (6, s, 2 x C ), 2.78 (4, s, (C 2 ) 2 ),

6 (, t, J., C), (, d, J 5 2.9, Ar-), (, dd, J 8.9, J 5 2.9, Ar-), (, d, J 8.9, Ar-), (0, m, -); δ C (00 Mz; CDCl ; Me 4 Si) 8.8 (C 2 ), 25.6 (2 x C 2 C=), 0.6 (C 2 ),.2 (C 2 ), 4.5 (2 x C ), 84.5 (C), 94. (C), 4.6, 4.9, 7., 25.4, 27.8, 28.0, 28., 29., 44.5, 44.6, 46.2 (all -C), 68.4 (C=), 69.0 (2 x C=); v max /cm - 00, 7, 652, 426, 5 RMS (ESI): found M +, (C requires ); m/z (ES) 57 (C 0 0 a 2 6, %), 55 (C 0 2 6, 8), 48 (7.5), 02 (00). 7 MR in CDCl 7 C MR in CDCl 6

7 2,2 -((xybis(ethane-2,-diyl))bis(oxy))diethanamine (8) was prepared according to the synthetic route described by umata et al. -(2-(2-(2-(2-Aminoethoxy)ethoxy)ethoxy)ethyl)-4-(6-(dimethylamino)-4,4-diphenyl-4benzo[d][,]dioxin-2-yl)butanamide ( ) S ester 7 (0.00 g, 0.95 mmol) in dichloromethane ( ml) was added dropwise to a solution of tetraethyleneglycol diamine 8 (0.49 g, mmol) in dichloromethane ( ml) over 0 minutes. The solution was stirred for 48 hours at room temperature and quenched with brine (0 ml). The aqueous layer was extracted with dichloromethane ( x 0 ml), the organic layers were combined and dried over MgS 4. The solution was evaporated to dryness and the residue purified by silica column chromatography (2:8:0. Me/C 2 Cl 2 /TEA) to yield compound as a colourless oil (0.09 g, 40%); R f 0.20 (:7 Me/C 2 Cl 2 ); δ (400 Mz; CDCl ; Me 4 Si) (4, m (C 2 ) 2 ), (2, m, C 2 ), 2.70 (6, s, 2 x C ), (2, t, J = 5. z, C 2 ),.9-.4 (2, m, C 2 ), (2, m, C 2 ), (2, m, C 2 ), (8, m, (C 2 ) 4 ), (, t, J 4.7, C), (, d, J 5.0, Ar-), (, bs, 2 ) (, dd, J 9.0 z, J 5.0 z, Ar-), (, d, J 9.0 z, Ar-), (0, m, -); δ C (00 Mz; CDCl ; Me 4 Si) 9.8 (C 2 ),.7 (C 2 C), 6.0 (C 2 C=), 9.2 (C 2 ) 40. (C 2 ), 4.4 (2 x C ), 67.9 (C 2 ), 69.7 (C 2 ), 70.0 (C 2 ) 70. (C 2 ), 84. (C), 94.6 (C), 4.4, 4.7, 7., 25.4, 27., 27.7, 27.8, 27.9, 28., 29.2, 29., 44.4, 44.5, 44.7, 46.2, (all -C), 7.6 (C=); v max /cm , 2985, 650, 525, 500, 255; RMS (ESI): found Ma +, (C a requires ); m/z (ES) 592 (C , 47%), 02 (45%), 242 (00). ' 2 MR in CDCl 7

8 ' 2 C MR in CDCl References. P. Wang, Y. Wang,. u, C. Spencer, X. Liang, and L. Pan, J. rg. Chem., 2008, 7, E. Vedejs, M. Arnost, and J. agen, J. rg. Chem., 979, 44, M. umata, K. Koumoto, M. Mizu, K. Sakurai, and S. Shinkai, rg. Biomol. Chem., 2005,,