Ir-Catalyzed Synthesis of Substituted Tribenzosilepins by Dehydrogenative C-H/Si-H Coupling.

The Ir-catalyzed intramolecular reaction of 2',6'-diaryl-2-(hydrosilyl)biphenyls gave substituted tribenzosilepins by direct dehydrogenative C-H/Si-H coupling. This is the first example of catalytic construction of the tribenzosilepin skeleton. Enantiomerically pure tribenzosilepin was prepared by optical resolution using chiral HPLC, and its inversion barrier was calculated by measurement of rate of racemization using the Eyring kinetic equation under heating conditions.

Pt-Catalyzed Enantioselective Cycloisomerization for the Synthesis of Planar-Chiral Ferrocene Derivatives.

Enantioselective cycloisomerization of 2-ethynyl-1-ferrocenylbenzene derivatives proceeded by using a chiral cationic platinum catalyst at room temperature. The intramolecular reaction gave planar-chiral naphthalene- and anthracene-fused ferrocene derivatives with high to excellent ee.