An Efficient, Practical, and Enantioselective Method for Synthesis of Homoallenylamides Catalyzed by an Aminoalcohol-Derived, Boron-Based Catalyst

作者：Wu Hao; Haeffner Fredrik; Hoveyda Amir H^*

来源：Journal of the American Chemical Society, 2014, 136(10): 3780-3783.

DOI：10.1021/ja500374p

A practical catalytic method for enantio-selective addition of an allene unit to aldimines is disclosed. Transformations are promoted by an in-situ-generated B-based catalyst that is derived from a simple, robust, and readily accessible (in multigram quantities) chiral aminoalcohol. A range of aryl-, heteroaryl-, and alkyl-substituted homoallenylamides can be obtained in 66-91% yield and 84:16 to %26gt;99:1 enantiomeric ratio through reactions performed at ambient temperature and in the presence of 0.1-3.0 mol% of the chiral catalyst and a commercially available allenylboron reagent. The catalytic protocol does not require strict anhydrous conditions, can be performed on gram scale, and promotes highly selective addition of an allenyl unit (vs a propargyl group). The utility of the approach is demonstrated through development of succinct approaches to syntheses of anisomycin and epi-cytoxazone.

• 出版日期2014-3-12