已经开发了一种通过外消旋乙烯基碳酸亚乙酯与水和醇的不对称烯丙基取代对映选择性构建叔 CO 键的有效方法。在温和条件下原位生成的手性钯配合物和硼试剂的协同催化系统下,该过程允许以高产率快速获得有价值的叔醇和醚,具有完整的区域选择性和高对映选择性。该协议代表了与作为氧供体的水直接对映选择性形成三级 CO 键的第一个例子。该过程的合成效用已通过将产品加工成生物相关制剂的关键中间体来证明,
heterogeneous palladium-catalyzed sulfonylation of vinylcyclic carbonates with sodium sulfinates via decarboxylative cross-coupling. Both aliphatic and aromatic sulfinate salts react with various vinylcyclic carbonates to deliver the desired allylic sulfones featuring tri- and even tetrasubstituted olefin scaffolds in high yields with excellent selectivity. The process needs only 2 mol% of Pd2(dba)3 and
Pd-Catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with 3-cyanochromones
作者:Ijaz Khan、Can Zhao、Yong Jian Zhang
DOI:10.1039/c8cc02456a
日期:——
of vinylethylene carbonates with 3-cyanochromones. By using a palladium complex generated in situ from [Pd2(dba)3]·CHCl3 and phosphoramidite L3 as a catalyst under mild reaction conditions, the process afforded furanobenzodihydropyrans bearing vicinal quaternary stereocenters in high yields with good to high enantio- and diastereoselectivities.
An efficient method for the enantioselective construction of β‐substituted β‐vinylglycinol derivatives through palladium‐catalyzed decarboxylative cycloaddition of vinylethylene carbonates with isocyanates was developed. By using a palladium complex generated in situ from [Pd2(dba)3]⋅CHCl3 (dba=dibenzylideneacetone) and (S)‐Segphos as a catalyst under mild reaction conditions, the process provided