Double-Stereodifferentiating Crotylation Reactions with Chiral <i>(E)</i>-Crotylsilanes. Evaluation of a New Approach for the Synthesis of Polypropionate-Derived Natural Products
作者:Nareshkumar F. Jain、Norito Takenaka、James S. Panek
DOI:10.1021/ja962877x
日期:1996.1.1
An efficient procedure for the preparation of chiral β-substituted (E)-crotylsilanes: Application of a rhodium(II) catalyzed silylformylation of terminal alkynes
作者:Nareshkumar F. Jain、Pier F. Cirillo、Jennifer V. Schaus、James S. Panek
DOI:10.1016/0040-4039(95)01894-n
日期:1995.11
β-substituted (E)-crotylsilanes (R)-7 and (S)-8, bearing an alkyl or aryl group adjacent to the stereogenic C-Si center have been synthesized in an efficient four-step procedure initiated with a regio- and stereoselective silylformylation of a terminal alkynecatalyzed by dirhodium(II) perfluorobutyrate.
Double stereodifferentiation in the lewis acid promoted crotylation of (S)-2-Alkoxypropanal with chiral β-Alkyl (E)-Crotylsilanes
作者:Nareshkumar F. Jain、Pier F. Cirillo、Roberta Pelletier、James S. Panek
DOI:10.1016/0040-4039(95)01895-o
日期:1995.11
induction have been evaluated in the Lewis acid promoted addition of (E)crotylsilanes (S)-1 and (R)-2 to (S)-2-alkoxypropanal 3 and 7. These aldehydes are substituted at the α-position with benzyloxy (OBn) to reinforce chelation and tert-butyldiphenylsilyloxy (TBDPSO) groups to prevent chelation with bidentate Lewis acids. The nature of the Lewis acid and the chirality of the silane reagent were found