Iron‐Promoted Domino Dehydrogenative Annulation of Deoxybenzoins and Alkynes Leading to β‐Aryl‐α‐Naphthols

Abstract

A strategy for synthesis of β‐aryl‐α‐naphthols has been established through an iron‐promoted domino C(sp3)−H/C(sp)−H and C(sp2)−H/C(sp)−H dehydrogenative coupling of deoxybenzoins and alkynes. The synthesis uses inexpensive materials with a broad substrate scope and features simple operations with excellent regioselectivity. This study provides an alternative access to various β‐aryl‐α‐naphthols and the synthetic protocol should have potential applications in medicinal, materials science, and related areas.magnified image

Fe‐Catalyzed Intramolecular Cross‐Dehydrogenative Arylation (CDA), Efficient Synthesis of 1‐Arylnaphthalenes and 4‐Arylcoumarins

“…[53 -60] Many excellent works of iron-catalyzed CDC reactions involve C(sp 3 )H bond activation have been reported. [36,[61][62][63][64][65][66][67][68][69][70][71] In 2009, we developed a Fe-catalyzed cross-dehydrogenation coupling reaction of electron-rich aromatic hydrocarbons and diphenylmethane [36] (Scheme 1,b). Based on our continuous research on the field of transition-metalcatalyzed oxidative coupling of unactivated CÀ H bonds, [36,72,73] we here developed an inexpensive, readily available FeCl 3 /DDQ system to efficiently catalyze the tandem cross-dehydrogenative arylation/ oxidation reaction of 1,4-diphenylbutane and (3phenoxypropyl) benzene towards the synthesis of 1arylnaphthalenes and 4-arylcoumarins (Scheme 1,c).…”

“…Among all of the reported transition metals, Fe was brought into focus because of its low toxicity, popular price, and environmentally benign features [53–60] . Many excellent works of iron‐catalyzed CDC reactions involve C( sp 3 )H bond activation have been reported [36,61–71] . In 2009, we developed a Fe‐catalyzed cross‐dehydrogenation coupling reaction of electron‐rich aromatic hydrocarbons and diphenylmethane [36] ( Scheme 1 ,b ).…”