Direct Titanium-Mediated Conversion of Ketones into Enamides with Ammonia and Acetic Anhydride
作者:Jonathan T. Reeves、Zhulin Tan、Zhengxu S. Han、Guisheng Li、Yongda Zhang、Yibo Xu、Diana C. Reeves、Nina C. Gonnella、Shengli Ma、Heewon Lee、Bruce Z. Lu、Chris H. Senanayake
DOI:10.1002/anie.201107601
日期:2012.2.6
A one‐step conversion of ketones into N‐acetyl enamides was developed. The process employs safe and inexpensive reagents, proceeds under mild conditions, and tolerates diverse functional groups. The addition of edte (N,N,N′,N′‐tetrakis(2‐hydroxyethyl)ethylenediamine) prior to workup enables water solubilization of Ti alkoxides and allows a simple extractive workup.
Hydrogen peroxide and anhydride mediated transformation of enamides to afford substituted α-acyloxy ketones is described. This transition-metal-free cascade reaction has a broad substrate scope and high efficiency. The acyl intramolecular migration procedure successfully achieved this acyloxylation process under mild conditions and increased the atom efficiency.