| Popis: |
This paper describes the synthesis of ( Z )-1-chlorovinyl sulfoxides 1 by the Horner-Wittig reaction. The required [(α-chloro)sulfinylmethyl]diphenylphosphine oxides 2 (R 1 =Me, c -Hex, Ph, p -Tol, p -(CF 3 )Ph), were prepared in high yields by selective monochlorination and subsequent monooxidation of (thiomethyl)diphenylphosphine oxides 3 . The stable lithiated anions of 2 gave an efficient reaction with all structural types of aldehydes. Aromatic and α,β-unsaturated aldehydes gave 1 with excellent Z -selectivity (> 98%), irrespective of the nature of the substituent R 1 at sulfur. With straight chain aliphatic aldehydes, an aromatic substituent at sulfur was required to obtain high Z -selectivity. A mechanistic explanation for these observations is presented. An X-ray analysis of 1 , R 1 =Me, R 2 =4-MeOC 6 H 4 confirmed the Z -disposition of the chloro and aryl substituents. |
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