Highly Selective Sequential Addition and Cyclization Reactions Involving Diphenyl Diselenide, an Alkyne, and Alkenes under Visible-Light Irradiation

✍ Scribed by Kaname Tsuchii; Mikio Doi; Toshikazu Hirao; Akiya Ogawa

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 131 KB
• Volume: 115
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/ange.200250790

✦ Synopsis

Dedicated to Professor Noboru Sonoda on the occasion of his 70th birthday

The development of highly selective carbon-carbon bondforming reactions with the simultaneous introduction of heteroatom functional groups is of great importance in organic synthesis. A variety of compounds with carboncarbon unsaturation can be utilized for this purpose. However, the use of several such unsaturated compounds together in a radical reaction usually results in their polymerization. In contrast, we have discovered that the addition of diphenyl diselenide, which has an appropriate carbon-radicalcapturing ability, depresses the undesired polymerization and makes it possible to carry out a highly selective sequential addition of (PhSe) 2 to unsaturated compounds. [3] Herein, we report a novel four-component coupling of an alkyne, two olefin molecules, and diphenyl diselenide, which proceeds through selective bond formation to connect these four molecules, and a subsequent 5-exo cyclization, as depicted in Scheme 1.

We started our study of this type of reaction by examining the combination of alkynes that bear an electron-withdrawing group with alkenes that bear an electron-donating group. When a mixture of ethyl propiolate (1), n-butyl vinyl ether Scheme 1. Sequential addition and cyclization strategy.