Air-Stable Solid Aryl and Heteroaryl Organozinc Pivalates: Syntheses and Applications in Organic Synthesis

作者:Manolikakes Sophia M; Ellwart Mario; Stathakis Christos I; Knochel Paul*
来源:Chemistry - A European Journal, 2014, 20(38): 12289-12297.
DOI:10.1002/chem.201403015

摘要

A wide range of air-stable, solid, polyfunctional aryl and heteroarylzinc pivalates were efficiently prepared by either magnesium insertion or Hal/Mg exchange followed by transmetalation with Zn(OPiv)(2) (OPiv = pivalate). By reducing the amount of LiCl the air stability could be significantly enhanced compared with previously prepared reagents. An alternative route is directed magnesiation using TMPMgCl center dot LiCl (TMP = 2,2,6,6-tetramethylpiperidyl) followed by transmetalation with Zn(OPiv)(2) or, for very sensitive substrates, direct zincation by using TMPZnOPiv. These zinc reagents not only show excellent stability towards air, but they also undergo a broad range of C-C bond-formation reactions, such as allylation and carbocupration reactions, as well as addition to aldehydes and 1,4-addition reactions. Acylation reactions can be performed by using an excess of TMSCl to overcome side reactions of the omnipresent pivalate anion.

  • 出版日期2014-9-15