Study and Applications of Tetrasubstituted Hypervalent Selenium–Halogen Species in Catalytic Electrophilic Halogenations
作者:Junjie Yang、Yung-Yin Chan、Weida Feng、Ying-Lung Steve Tse、Ying-Yeung Yeung
DOI:10.1021/acscatal.2c05414
日期:2023.2.17
Electrophilic halogenation reactions are highly useful in various areas. N-Haloamides are commonly used as halogen sources because of high stability and commercial availability. In order to activate N-haloamides, Lewis basic chalcogens are commonly used as catalysts to site-isolate the strongly coordinating amide moieties. However, the corresponding trisubstituted chalcogenonium–halogen cationic intermediate
亲电卤化反应在各个领域都非常有用。由于高稳定性和商业可用性,N-卤代酰胺通常用作卤素源。为了激活N- 卤代酰胺,路易斯碱性硫属元素通常用作催化剂以将强配位的酰胺部分隔离。然而,相应的三取代硫属元素-卤素阳离子中间体对水分和亲核试剂敏感,导致在某些反应中相容性差。在此,我们报告了一种有效的催化卤化方案,使用苯基硒和邻位取代的羧酸作为催化剂。机理研究表明,四取代的中性高价硒-卤素物种是造成高反应性的原因。这种活性中间体被发现对水分稳定,催化体系适用于广泛的亲电功能化反应,包括卤代酰胺化、分子间卤代酯化、卤代环醚化、卤代内酯化、芳族卤代、