Cobalt-Catalyzed Annulation of Salicylaldehydes and Alkynes to Form Chromones and 4-Chromanones
作者:Junfeng Yang、Naohiko Yoshikai
DOI:10.1002/anie.201510999
日期:2016.2.18
A unique cobalt(I)–diphosphine catalytic system has been identified for the coupling of salicylaldehyde (SA) and an internal alkyne affording a dehydrogenative annulation product (chromone) or a reductive annulation product (4‐chromanone) depending on the alkyne substituents. Distinct from related rhodium(I)‐ and rhodium(III)‐catalyzed reactions of SA and alkynes, these annulation reactions feature