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[摘要]:A highly efficient and enantioselective synthesis of axially chiral alpha-allenols was realized in practical yields with 96-99% ee or de from TBS-protected propargylic alcohols, aldehydes, and a commercially available, inexpensive, chiral, secondary amine (S)-alpha,alpha-diphenylprolinol or its enantiomer followed by desilylation. The easily removable TBS group not only acts as a protecting group, but also as a possible sterically directing group for the excellent enantioselectivity and in situ prevention of possible allene racemization. |
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