Silicon-Based Cross-Coupling Reactions Through Intramolecular Activation

Abstract

Tetraorganosilanes having a 2-(hydroxymethyl)phenyl group are found to undergo the silicon-based cross-coupling reaction. The proximal hydroxy group allows transmetalation of alkyl, alkenyl, and aryl groups on silicon to palladium(II), nickel(II), or copper(I or II) to occur, and hence participation in the cross-coupling reaction under mild conditions with excellent chemoselectivity. The high stability of the tetraorganosilicon structure is demonstrated by functionalization under various acidic, basic, and oxidative conditions which leave the silyl group completely intact. Moreover, highly efficient synthesis of functional molecules such as oligoarenes has been achieved through iterative cross-coupling/O-deprotection sequences by simply switching reactivity with orthogonal O-protection/deprotection.