Catalytic Intramolecular Hydrofunctionalization of Unactivated Alkenes and Alkynes

Catalytic intramolecular hydrofunctionalizations of acyclic alkenes and alkynes are desired methods for the construction of pharmaceutically important heterocycles with 100% atom efficiencies. Although electrophilic activation of alkenes and alkynes in the presence of Lewis basic hydroxy and amino groups can cause the reactions, those of monoalkyl - and 1,2 - dialkyl- substituted alkenes and alkynes called unactivated alkenes and alkynes are difficult owing to their inherent reactivity. Herein, we introduce several transition metal - free novel catalytic systems for the intramolecular hydrofunctionalization of such unactivated alkenes and alkynes; iodine- silane catalytic system for the hydroalkoxylation of unactivated alkenes, Bronsted acid -silane and iodinesilane catalytic systems for the hydrofunctionalization/reduction of unactivated alkynes, and boron catalytic systems for double hydrofunctionalization reactions of unactivated alkynes. A novel active species, iodophenylsilane(PhSiH2I)efficiently catalyzes the intramolecular hydroalkoxylation of unactivated alkenes in the iodine -silane catalytic system. A super strong Bronsted acid catalyst can activate unactivated alkynes in the presence of silane to cause the hydrofunctionalization/ reduction. Tris(pentafluorophenyl)borane [B(C6F5)(3)] chemoselectively activates unactivated alkynes in the presence of allylsilane to cause the intramolecular hydrofunctionalization/hydroallylation. In addition, tris(pentafluorophenyl)borane hydrate[B(C6F5)(3)center dot nH(2)O]reacts with trimethylsilylcyanide to form H+[NCB(C6F (5))(3)](-), which catalyzes the intramolecular hydroalkoxylation/ hydrocyanation of unactivated alkynes. These catalytic methods enable the rapid construction of multiply -substituted oxygen - or nitrogen- containing heterocycles.