Oxidative Coupling of Terminal Alkynes with Aldehydes Leading to Alkynyl Ketones by Using Indium(III) Bromide.
An indium(III)-promoted direct acylation of terminal alkynes using aldehydes leading to ynones was developed. In contrast to the previous addition reactions of alkynes to aldehydes, which provide propargylic alcohols, the oxidative coupling proceeded exclusively to afford alkynyl ketones. The products were likely generated through an Oppenauer oxidation of the indium propargylic alkoxide species by excess amounts of aldehydes.
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan).
Yohei
Y
Ogiwara
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan).
Masahito
M
Kubota
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan).
Kotaro
K
Kurogi
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan).
Takeo
T
Konakahara
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan). sakachem@rs.noda.tus.ac.jp.
Norio
N
Sakai
CC coupling reaction; acylation; alkynes; hydrogen transfer; indium