Yttrium-Catalyzed Amine–Silane Dehydrocoupling: Extended Reaction Scope with a Phosphorus-Based Ligand

The scope of the catalytic dehydrocoupling of primary and secondary amines with phenylsilanes has been investigated using [Y­{N­(SiMe₃)₂}₃] and a four-coordinate analogue bearing a cyclometalated phosphonium methylide ligand. Inclusion of the phosphorus-based ligand on yttrium results in increased substrate scope in comparison to the tris­(amide) analogue. While reversible C–H bond activation of the cyclometalated ligand was observed in stoichiometric experiments, D-labeling experiments and DFT calculations suggest that reversible ligand activation is not involved in silazane formation under catalytic conditions. We suggest that the extended reaction scope with the four-coordinate yttrium phosphonium methylide complex relative to the three-coordinate yttrium (tris)­amide complex is a result of differences in the ease of amine inhibition of catalysis

Weakly Coordinated Zinc and Aluminum σ‑Complexes of Copper(I)

We report the synthesis and isolation of three new σ-complexes of Cu­(I) in which E–H (E = Al, Zn) σ-bonds are coordinated to copper. The addition of the main group hydride to a toluene-solvated Cu­(I) complex results in reversible ligand exchange, and the Cu­(I) σ-complexes have been crystallized. Experimental and computational data provide a wealth of evidence for weak binding of the E–H bond to Cu­(I), which can be ascribed to σ-donation from the E–H bond into the 4s orbital of copper and back-donation from copper into the E–H σ* orbital

A Highly Chemoselective, Zr-Catalyzed C–O Bond Functionalization of Benzofuran

The chemoselective C–O bond functionalization of benzofuran with an aluminum dihydride may be catalyzed by zirconocene dichlorides. The reaction proceeds with the formal addition of a C–O bond to, and elimination of dihydrogen from, aluminum. The product of C–O bond alumination reacts with benzaldehyde via insertion of the carbonyl into the newly formed Al–C bond