Synlett 2016; 27(07): 1128-1132
DOI: 10.1055/s-0035-1561098
letter
© Georg Thieme Verlag Stuttgart · New York

Photochemical and Additive-Free Coupling Reaction of α-Cumyl α-Keto Esters via Intermolecular C–H Bond Activation

Eisuke Ota
a  Synthetic Organic Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
b  Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
,
Yu Mikame
a  Synthetic Organic Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
c  Department of Life Science and Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo, 184-8588, Japan
,
Go Hirai*
a  Synthetic Organic Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
d  RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
e  AMED-CREST, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan   Email: gohirai@riken.jp   Email: sodeoka@riken.jp
,
Shigeru Nishiyama
b  Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
,
Mikiko Sodeoka*
a  Synthetic Organic Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
d  RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
e  AMED-CREST, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan   Email: gohirai@riken.jp   Email: sodeoka@riken.jp
› Author Affiliations
Further Information

Publication History

Received: 26 November 2015

Accepted after revision: 14 December 2015

Publication Date:
04 January 2016 (eFirst)

Abstract

We developed a photo-chemical coupling reaction of α-keto esters with several simple alcohols, alkanes, ethers, and amides. Use of tertiary alkyl ester, α-cumyl ester, is the key for avoiding the known photo-degradation process. Intermolecular C–H bond activation and subsequent C–C bond formation were promoted by irradiation with an LED lamp (365 nm) without any additives. Among the coupling partners, reactions with sterically less demanding amides proceeded efficiently to provide unique N-acyl-β-amino-α-hydroxy acid derivatives. In benzene or acetone as a solvent, the reaction with a solid amino acid derivative provided a precursor of tetrahydro-1,4-diazepine-2,5-dione derivatives.

Supporting Information

 
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