Addition of dienolates to sulfinimines. Stereoselective synthesis of dihydropyridones
摘要:
The vinylogous Mannich reaction of sulfinimines with dienolates was investigated. Lithium and trimethylsilyl enolates of ethyl 3-ethoxycrotonate reacted with enantiopure 10-isobornylsulfinimines to give derivatives of delta -aminoacids which were cyclised to 6-aryl substituted derivatives of 2(1H)-pyridinones. 6-Aryl substituted 2,4-piperidinediones with either (S) or (R) configuration were analogously obtained using lithium and TMS enolates of 2,2,6-trimethyl-1,3-dioxin-4-one. (C) 2001 Elsevier Science Ltd. All rights reserved.
Aza Diels–Alder reactions of sulfinimines with the Rawal diene
作者:Robert Kawęcki
DOI:10.1016/j.tetasy.2006.04.026
日期:2006.5
The azaDiels–Alderreaction of optically active sulfinimines with the Rawal diene leads to enantiomerically enriched dihydropyridones with ees up to 90%. The reaction was catalyzed by TMSOTf. The best results were obtained using 10-isobornylsulfinimines. Removal of the sulfinyl auxiliary occurred during workup of the reaction mixture. The reaction most likely proceeds via a stepwise mechanism. The
New, recoverable and highly effective sulfinyl chiral auxiliary
作者:Robert Kawęcki
DOI:10.1016/s0957-4166(03)00624-4
日期:2003.9
A facile synthesis of a bicyclic 8-menthylsulfinate is described. The reaction of this sultine with organometallic compounds leads to gamma-hydroxysulfoxides, while the reaction with lithium amide affords 8-menthylsulfinamide. The chiral efficiency of the 8-menthylsulfinyl auxiliary was tested in the reaction of sulfinimines with Grignard reagents. A highly stereoselective addition of ethylmagnesium bromide to 8-menthylsulfinimine was observed (98% de). (C) 2003 Elsevier Ltd. All rights reserved.