Umpolung Pd-Catalyzed α-Arylation Reactions in Natural Product Synthesis: Syntheses of (+)-Xestodecalactone A, (-)-Curvularin, (+)-12-Oxocurvularin and (-)-Citreofuran
作者:Dripta De Joarder、Michael P. Jennings
DOI:10.1002/ejoc.201500287
日期:2015.5
of complex α-bromo esters and boronic acids under mild reaction conditions. As part of the synthetic approaches to these natural products, it was observed that the mild coupling reaction conditions readily tolerated terminal alkenes, other labile ester functionalities, an α,β-unsaturated ester moiety, and a protected allylic alcohol, while chemoselectively engaging the α-bromo ester. The completion of
四种苯乙酸内酯 (PAL) 天然产物的合成(总的和缩醛的)是通过在温和的反应条件下利用 umpolung Pd 催化的复杂 α-溴酯和硼酸的 α-芳基化的统一策略完成的。作为这些天然产物合成方法的一部分,观察到温和的偶联反应条件容易耐受末端烯烃、其他不稳定的酯官能团、α,β-不饱和酯部分和受保护的烯丙醇,同时化学选择性地参与 α -溴酯。(+)-xestodecalactone A 和 (-)-curvularin 的完成以及 (+)-12-oxocurvularin 和 (-)-citreofuran 的正式合成突出了 umpolung Pd 催化的 α-芳基化策略作为关键的收敛策略复杂的天然产物合成。