Rhodium‐Catalyzed Intramolecular C−H Silylation by Silacyclobutanes. Issue 21 (13th April 2016) - Zhang, Qing‐Wei
Abstract: Silacyclobutane was discovered to be an efficient C−H bond silylation reagent. Under the catalysis of Rh I /TMS‐segphos, silacyclobutane undergoes sequential C−Si/C−H bond activations, affording a series of π‐conjugated siloles in high yields and regioselectivities. The catalytic cycle was proposed to involve a rarely documented endocyclic β‐hydride elimination of five‐membered metallacycles, which after reductive elimination gave rise to a Si−Rh I species that is capable of C−H activation. Abstract : Old reagent, new reactivity : Silacyclobutane was discovered to be an efficient C−H bond silylation reagent under the catalysis of Rh/TMS‐segophos. This new reactivity was attributed to a key Si−Rh I intermediate formed through a Si−C activation, endocyclic β‐H elimination and reductive elimination cascade. A wide array of siloles was obtained in high yields and excellent regioselectivities.