Three-Component Reactions with Sterically Crowded 2,2,4,4-Tetramethyl-3-thioxocyclobutanone, Phenyl Azide, and Electron-Deficient C,C-Dipolarophiles
✍ Scribed by Grzegorz Mlostoń; Jaroslaw Romańnski; Anthony Linden; Heinz Heimgartner
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- German
- Weight
- 540 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
Dedicated to Professor Vludimir Prelog on the occasion of his 90th birthday (8.V.96)
In order to trap 'thiocarbonyl-aminides' A, formed as intermediates in the reaction of thiocarbonyl compounds with phenyl azide, a mixture of 2,2,4,4-tetramethyl-3-thioxocyclobutanone (l), phenyl azide, and fumarodinitrile (8) was heated to 80" until evolution of N, ceased. Two interception products of the 'thiocarbonylaminide' A (Ar = Ph) were formed: the known 1,4,2-dithiazolidine 3 (cf: Scheme 1 ) and the new 1,2-thiazolidine 12 (Scheme 2). The structure of the latter was established by X-ray crystallography (Fig. I). The analogous 'threecomponent reaction' with dimethyl fumarate (9) yielded, instead of 8, in addition to the known interception products 3 and 6 (Scheme I), two unexpected products 15 and 16 (Scheme 3 ) , of which the structures were elucidated by X-ray crystallography (Fig. 2). Their formation is rationalized by a primary [2 + 31 cycloaddition of diazo compound 18 with 1 to give 19, followed by a cascade of further reactions (Scheme 4 ) .
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Presented by G. M . at the '17th International Symposium on the Organic Chemistry of Sulfur', Tsukuba, Japan, July 1996. The names 'thiocarbonyl-aminide' and 'thiocarbonyl-thiolate' are short forms for 'N-(alkylidenesu1fonio)aminide' and 'S-(alkylidenesulfonio)thiolate', respectively; commonly these classes of S-centered 1,3-dipoles are named 'thiocarbonyl S-imides' and 'thiocdrbonyl S-sulfides', respectively.
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Recently, Roesky et ul. described 1,3-dipolar cycloadditions of a stable bis(trifluoromethy1)-substituted 'thiocarbonyl S-imide' with some alkenes [12].