Efficient synthetic methods towards mixed aliphatic carbonates through the three component couplings of aliphatic alcohols, alkyl halides and carbon dioxide in the presence of cesium carbonate and tetrabutylammonium iode (TBAI). Due to their enhanced nucleophilicities, cesium alkoxides are smoothly incorporated into CO2, allowing for mild reaction conditions such as ambient temperatures and short reaction durations. Various primary and secondary substrates are compatible under the standard conditions, offering high yields, while chiral templates such as &agr;-hydroxy carbonyls are resistant to racemization.
通过使用硬碱性化合物
氢氧化铯和
四丁基碘化铵(TBAI)的存在下,通过脂肪族醇、烷基卤代物和
二氧化碳的三组分偶联反应,实现了高效的混合脂肪族
碳酸酯的合成方法。由于其增强的亲核性,
铯醇可以顺利地与
二氧化碳结合,从而实现温和反应条件,如常温和短反应时间。在标准条件下,各种一级和二级底物均兼容,提供高收率,而手性模板如α-羟基羰基化合物则不易发生外消旋化。