Efficient and Convenient Procedure for Preparation of<i>N</i>‐Sulfonylimines Catalyzed by Montmorillonite K‐10
作者:Tong‐Shou Jin、Mi‐Jun Yu、Li‐Bin Liu、Ying Zhao、Tong‐Shuang Li
DOI:10.1080/00397910600640073
日期:2006.8
A general and practical chemical route to the synthesis of N-sulfonylimines using montmorillonite K-10 as the catalyst is described. This method provides several advantages such as operational simplicity, short reaction time, using of inexpensive materials, noncorrosivity, lack of pollution, and high yields.
Synthesis and Catalytic Application of Chiral 1,1‘-Bi-2-naphthol- and Biphenanthrol-Based Pincer Complexes: Selective Allylation of Sulfonimines with Allyl Stannane and Allyl Trifluoroborate
作者:Juhanes Aydin、K. Senthil Kumar、Mahmoud J. Sayah、Olov A. Wallner、Kálmán J. Szabó
DOI:10.1021/jo070288b
日期:2007.6.1
New easily accessible 1,1'-bi-2-naphthol- (BINOL-) and biphenanthrol-based chiral pincer complex catalysts were prepared for selective (up to 85% enantiomeric excess) allylation of sulfonimines. The chiral pincer complexes were prepared by a flexible modular approach allowing an efficient tuning of the selectivity of the catalysts. By employment of the different enantiomeric forms of the catalysts, both enantiomers of the homoallylic amines could be selectively obtained. Both allyl stannanes and allyl trifluoroborates can be employed as allyl sources in the reactions. The biphenanthrol-based complexes gave higher selectivity than the substituted BINOL-based analogues, probably because of the well-shaped chiral pocket generated by employment of the biphenanthrol complexes. The enantioselective allylation of sulfonimines presented in this study has important implications for the mechanism given for the pincer complex-catalyzed allylation reactions, confirming that this process takes place without involvement of palladium(0) species.
NOUVELLE VOIE DE SYNTHESE DE DIAZIRINES, ENRICHIES OU NON EN AZOTE-15