利用有機膦試劑使α,β-不飽和羰基化合物與醯氯進行β醯化反應

Abstract

近年來，本實驗室開發出一系列具有α,β-不飽和羰基的化合物作為起始物，並在有機膦試劑作用下，能得到β位醯化反應 (β-acylation)的產物，接著我們嘗試改變我們起始物的結構，使用鏈狀的α,β-不飽和羰基的化合物期望一樣能進行β位醯化反應。 首先我們利用查爾酮衍生物，其同樣具有α,β-不飽和羰基的結構，能在膦試劑的作用下進行β位醯化反應，並利用控制實驗探討其進行β位醯化反應的成因以及限制。 同時我們也嘗試改變起始物結構，以肉桂酸在鹼試劑的條件下與醯氯反應得到具有α,β-不飽和羰基結構的酸酐，接著會經由β位醯化反應的中間產物，其會繼續被膦試劑加成，最終得到呋喃酮的產物。

We report an organophosphane-promoted direct β-acylation of α,β-unsaturated 1,3-diketones with acyl chlorides in presence of the base. The systematic mechanistic investigations reveal that the α,β-unsaturated 1,3-diketone with electron-donating group at 2nd position favours the reaction toward the formation of β-acylated products where electron-withdrawing group follows the reaction toward the C-acylation/cyclization sequence. The obtained β-acylation adducts could be further transformed into furan derivatives.

The method for the synthesis of 2-furanones was also demonstrated by the reaction of cinnamic acid derivatives and acyl chlorides via the β-acylation of corresponding cinnamic anhydride derivatives as the key step.