A Mismatch-Free Strategy for the Diastereoselective alpha,alpha-Bisalkylation of Chiral Nonracemic Methyl Ketones

作者:Uddin Md Nasir; Tarsis Emily M; Wu Chia Hua; Wu Judy I; Coltart Don M*
来源:Organic Letters, 2018, 20(13): 3723-3727.
DOI:10.1021/acs.orglett.8b01146

摘要

A chiral auxiliary-based diastereoselective transformation that entirely avoids the stereochemically mismatched pairing, providing equally high levels of asymmetric induction in the formation of each diastereomer is described. In particular, we show that chiral nonracemic methyl ketones undergo alpha,alpha-bisalkylation using phenylalanine-derived N-amino cyclic carbamate (ACC) auxiliaries with essentially perfect diastereoselectivity, as well as excellent yield and regioselectivity. Significantly, with the use of a single enantiomer of the auxiliary, either diastereomeric product can be synthesized with an equally high level of asymmetric induction.

  • 出版日期2018-7-6