Gao Ge, Xie Ru-Gang, Pu Lin
Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA.
Proc Natl Acad Sci U S A. 2004 Apr 13;101(15):5417-20. doi: 10.1073/pnas.0307136101. Epub 2004 Mar 16.
It is found that the addition of hexamethylphosphoramide to the solution of an alkyne, Et(2)Zn, and (S)-1,1'-bi-2-naphthol in methylene chloride allows the generation of an alkynylzinc at room temperature and shows highly enantioselective additions to aldehydes. The mild condition for the formation of the alkynylzinc reagent enables the use of functional alkynes in this asymmetric reaction with excellent enantioselectivity. It avoids the reflux of the toluene solutions of the alkynes and Et(2)Zn as previously reported.
研究发现，在二氯甲烷中，向炔烃、二乙基锌和（S）-1,1'-联二萘酚的溶液中加入六甲基磷酰胺，可在室温下生成乙炔基锌，并对醛表现出高度对映选择性加成。乙炔基锌试剂形成的温和条件使得在该不对称反应中能够使用官能化炔烃，且对映选择性优异。它避免了如先前报道的炔烃和二乙基锌的甲苯溶液回流。
