Synthesis of α-Keto-Imides via Oxidation of Ynamides
作者:Ziyad F. Al-Rashid、Whitney L. Johnson、Richard P. Hsung、Yonggang Wei、Pei-Yuan Yao、Renhei Liu、Kang Zhao
DOI:10.1021/jo8015067
日期:2008.11.21
A de novo preparation of alpha-keto-imides via ynamide oxidation is described. With a number of alkyne oxidation conditions screened, a highly efficient RuO2-NaIO4 mediated oxidation and a DMDO oxidation have been identified to tolerate a wide range of ynamide types. In addition to accessing a wide variety of a-keto-imides, the RuO2-NaIO4 protocol provides a novel entry to the vicinal tricarboryl motif via oxidation of push-pull ynamides, and imido acylsilanes from silyl-substituted ynamides. Chemoselective oxidation of ynamides containing olefins can be achieved by using DMDO, while the RuO2-NaIO4 protocol is not effective. These studies provide further support for the synthetic utility of ynamides.
Aqueous ZnCl<sub>2</sub> Complex Catalyzed Prins Reaction of Silyl Glyoxylates: Access to Functionalized Tertiary α-Silyl Alcohols
作者:Man-Yi Han、Hong Pan、Pinhua Li、Lei Wang
DOI:10.1021/acs.joc.9b03501
日期:2020.5.1
An efficient Prins reaction of silyl glyoxylates in the presence of an aqueous ZnCl2 complex as a catalyst was developed, providing functionalized tertiary α-silyl alcohols in high yields under mild conditions. A preliminary investigation indicated that the aqueous ZnCl2 complex acted as a dual functional catalyst of Brønsted and Lewis acid to activate the carbonyl groups of silyl glyoxylates via a