KHSO<sub>4</sub>-Mediated Condensation Reactions of <i>tert</i>-Butanesulfinamide with Aldehydes. Preparation of <i>tert</i>-Butanesulfinyl Aldimines
作者:Yong Qin、Zhiyan Huang、Min Zhang、Yin Wang
DOI:10.1055/s-2005-865234
日期:——
tert-butanesulfinyl aldimines 1 were prepared by direct condensation of chiral tert-butanesulfinamide 3 with aldehydes 2 in high yields in the presence of KHSO 4 . The main advantage of KHSO 4 is that it is applicable to the condensation reactions of a variety of aldehydes, including electron deficient and electron rich (hetereo)aromatic aldehydes, as well as aliphatic aldehydes.
Diastereoselective Pomeranz–Fritsch–Bobbitt synthesis of (S)-(−)-O-methylbharatamine using (S)-N-tert-butanesulfinimine as a substrate
作者:Agnieszka Grajewska、Maria D. Rozwadowska
DOI:10.1016/j.tetasy.2007.11.010
日期:2007.12
The protoberberine-type alkaloid, (S)-(-)-O-methylbharatamine, has been synthesized in six steps involving the addition of laterally lithiated o-toluamide to (S)-N-tert-butanesulfinimine as the crucial process. The target alkaloid was obtained in 24.4% overall yield with 88% ee. (c) 2007 Elsevier Ltd. All rights reserved.
Highly Diastereoselective Enolate Addition of O-Protected α-Hydroxyacetate to (<i>S</i><i><sub>R</sub></i>)-<i>tert-</i>Butanesulfinylimines: Synthesis of Taxol Side Chain
[GRAPHICS]The taxol side chain (S-R,2R,3S)-N-tert-butanesulfinyl-O-Boe-3-phenylisoserine benzyl ester 4c was synthesized through a lithium enolate addition of O-Boc-alpha-hydroxyacetate benzyl ester 5c to benzylidene (S-R)-tert-butanesulfinamide 6a in excellent yield and diastereoselectivity. By similar approach, a series of enantiopure 3-substituted isoserine benzyl esters 4 useful for the semi-syntheses of taxol derivatives were also prepared in high to excellent yields and diastereoselectivities. The diastereoselective addition mechanism was discussed on the basis of the experimental observation.