FUSED PHOSPHONO SUBSTITUTED O-, AND N-HETEROCYCLES via CONDENSATIVE CYCLISATION REACTIONS OF α-PHOSPHONYL CARBANIONS WITH 4-THIAZOLIDINONES

Abstract

Phosphono substituted-thiazolones 5a, b together with fused phosphono-pyran-5-ones 9a, b and the diolefins 8a–d were regioselectively prepared in reasonable yields from the reactions of 5-arylidene-4-thiazolidinones 1a, b with phosphonoacetates 2a, b. Conversely, Michael addition products 11a, b (∼30%) along with the phosphono substituted-thiazole derivatives 12a, b (∼33%) were obtained from treating 1a, b with cyanomethylenephosphonates (2c). The reactions of 1a, b with vinylphosphonate 2d proceeded with phase-transfer catalysis, yielding the corresponding 2-thioalkyl-derivatives 14a, b and phosphonates 13a, b.

Keywords:

• 4-Thiazolidinones
• condensative cyclization reaction
• phosphonyl carbanions