Unexpected B/Al Transelementation within a Rh Pincer Complex.

Authors :: Lai Q
Bhuvanesh N
Ozerov OV
Source :: Journal of the American Chemical Society [J Am Chem Soc] 2020 Dec 16; Vol. 142 (50), pp. 20920-20923. Date of Electronic Publication: 2020 Dec 02.
Publication Year :: 2020
Abstract: We report the synthesis of PAlP and PBP pincer complexes of Rh with a central bis( N -pyrrolyl)aluminyl or -boryl unit. Complex (PAl <superscript>py</superscript> P)Rh(CO) <subscript>2</subscript> possesses an aluminyl site stabilized by coordination of pyridine, resulting in a four-coordinate Al. Attempts to access the three-coordinate aluminyl by abstraction of pyridine with BF <subscript>3</subscript> ·Et <subscript>2</subscript> O unexpectedly led to a B/Al metathesis with the preservation of the pincer structure in the product (PBP)Rh(CO) <subscript>2</subscript> . Abstraction of pyridine was carried out using B(C <subscript>6</subscript> F <subscript>5</subscript> ) <subscript>3</subscript> , but the desired (PAlP)Rh(CO) <subscript>2</subscript> underwent dimerization via isocarbonyl bridging.