Traditionally, α,β-unsaturated carboxylic acids have been prepared by utilization of named reactions such as the Wittig reaction, Doebner − Knoevenagel reaction, and Horner − Wadsworth − Emmons reaction. However, most of these protocols, if not all, suffer from restricted substrate scope, low levels of regio- and stereoselectivity and/or generation of a large amount of waste streams. Thus, the development of a convenient and efficient protocol for the regio- and stereocontrollable synthesis of the titled compounds using low-cost and easily accessible starting materials remains a big challenge. Recently, hydrocarboxylation of alkynes by employing carbon dioxide (CO₂) was developed in the presence of various metal catalysts which allow the synthesis of α,β-unsaturated carboxylic acids, with the benefits of high atom economy, high product yield and good regio- and stereoselectivity. The purpose of this review is to provide an overview of the recent progress and developments in this appealing synthetic procedure, with an emphasis on the mechanistic aspects of the reactions.

传统上，通过使用命名反应如Wittig反应，Doebner-Knoevenagel反应和Horner-Wadsworth-Emmons反应来制备α，β-不饱和羧酸。但是，这些协议中的大多数（如果不是全部的话）都受到受限制的底物范围，低水平的区域选择性和立体选择性和/或大量废物流的产生。因此，为使用低成本和易于获得的起始原料进行区域和立体可控的标题化合物的合成进行方便和有效的方案的开发仍然是一个巨大的挑战。最近，通过使用二氧化碳（CO ₂）是在各种金属催化剂的存在下开发的，这些催化剂可以合成α，β-不饱和羧酸，具有高原子经济性，高产物收率以及良好的区域选择性和立体选择性的优点。这篇综述的目的是概述这种吸引人的合成方法的最新进展和发展，重点是反应的机理方面。