کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1348152 980342 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chiral Ti(IV) complexes of hexadentate Schiff bases as precatalysts for the asymmetric addition of TMSCN to aldehydes and the ring opening of cyclohexene oxide
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Chiral Ti(IV) complexes of hexadentate Schiff bases as precatalysts for the asymmetric addition of TMSCN to aldehydes and the ring opening of cyclohexene oxide
چکیده انگلیسی

Chiral dinuclear titanium(IV) complexes (generated in situ from hexadentate Schiff bases and titanium tetra-isopropoxide) have been found to be more effective catalysts for the asymmetric addition of trimethylsilyl cyanide to aldehydes and the ring opening of cyclohexene oxide than their mononuclear analogues. The best results were obtained for benzaldehyde (86% enantiomeric excess) and cyclohexene oxide (89% enantiomeric excess).

Figure optionsDownload as PowerPoint slide

3,3′-[((S)-1-Hydroxymethyl-2-methylpropyl)imino]methyl-2,2′-dihydroxy-1,1′-biphenylC24H32N2O4Ee = 100%[α]D25=-143.8 (c 1, MeOH)Source of chirality: synthesis from (S)-valineAbsolute configuration: (S,S)

3,3′-[((S)-1-Hydroxymethyl-2-methylpropyl)imino]methyl-2,2′-dihydroxy-(R)-1,1′-binaphthaleneC32H36N2O4Ee = 100%[α]D25=-139.8 (c 1, CHCl3)Source of chirality: synthesis from (S)-valine and (R)-binolAbsolute configuration: (S,S,aR)

3,3′-[((S)-1-Hydroxymethyl-2-methylpropyl)imino]methyl-2,2′-dihydroxy-(S)-1,1′-binaphthaleneC32H36N2O4Ee = 100%[α]D25=-163 (c 1, CHCl3)Source of chirality: synthesis from (S)-valine and (S)-binolAbsolute configuration: (S,S,aS)

N-(2-Hydroxy-3,5-di-tert-butyl-benzylidene)-(S)-2-amino-3-methylbutan-1-olC20H33NO2Ee = 96.6%[α]D25=-33.3 (c 0.78, MeOH)Source of chirality: synthesis from (S)-valineAbsolute configuration: (S)

N-(2-Hydroxybenzylidene)-(S)-2-amino-3-methylbutan-1-olC12H17NO2Ee = 96.6%[α]D25=-25.0 (c 0.8, MeOH)Source of chirality: synthesis from (S)-valineAbsolute configuration: (S)

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron: Asymmetry - Volume 17, Issue 16, 25 September 2006, Pages 2328–2333
نویسندگان
, , , , , , ,