Gold-to-Boron Aryl Transfer from a T-Shaped Phosphine-Borane Gold(I) Complex

T-shaped gold(I) complexes with significant Au -> B interactions were prepared from the phosphine-borane i-Pr2P(o-C6H4)BFXyl(2) [Fxyl = 3,5-(F3C)(2)C6H3]. The (P,B)AuArF complex 4 [Ar-F = 4-(F3C)C6H4] was obtained by an indirect route involving ligand exchange from (ArO)(3)PAuArF 3a [Ar = 2,4-(t-Bu)(2)C6H3]. A different outcome was observed with the analogous precursor (MeO)(3)PAuArF 3b. Here, the phosphite remains bonded to gold, and the borane moiety abstracts the Ar-F group from gold to give the zwitterionic dicoordinate gold(I) complex 5. DFT calculations support a 2-step associative pathway for this gold-to-boron aryl transfer. It involves a square-planar gold(I) complex with enhanced Au -> B interaction as key intermediate and proceeds via via a 3-center transition state.

Automated summary

This study investigates the interaction between gold(I) complexes and boron, revealing a 2-step associative pathway for gold-to-boron aryl transfer. Experimental and theoretical results shed light on the mechanism involved in the transfer reaction, providing new insights into the behavior of these T-shaped gold complexes.