Net heterolytic cleavage of B-H and B-B bonds across the N-Pd bond in a cationic (PNP)Pd fragment

Yanjun Zhu; Chun-Hsing Chen; Claudia M Fafard; Bruce M Foxman; Oleg V Ozerov

doi:10.1021/ic2001283

Net heterolytic cleavage of B-H and B-B bonds across the N-Pd bond in a cationic (PNP)Pd fragment

Inorg Chem. 2011 Sep 5;50(17):7980-7. doi: 10.1021/ic2001283. Epub 2011 Aug 5.

Authors

Yanjun Zhu¹, Chun-Hsing Chen, Claudia M Fafard, Bruce M Foxman, Oleg V Ozerov

Affiliation

¹ Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77842, USA.

PMID: 21819075
DOI: 10.1021/ic2001283

Abstract

The use of weakly coordinating anions BAr(F)(4) (where Ar(F) = 3,5-(CF(3))(2)C(6)H(3)) and CB(11)H(12) allows one to access clean reactions of the [(PNP)Pd](+) fragment (PNP = bis(2-(i)Pr(2)P4-Me-phenyl)amido) with the B-H bond in catecholborane (CatBH) and catecholdiboron (CatBBCat). In both cases, a net heterolytic cleavage of B-H or B-B takes place, with the nitrogen atom of PNP being a recipient of a boryl fragment. The resultant products [(PN(BCat)P)PdH](+) (2) and [(PN(BCat)P)PdBCat](+) (3) were isolated as either BAr(F)(4) or CB(11)H(12) salts and fully characterized. They are susceptible to hydrolysis, with the B-N bond hydrolyzing selectively and rapidly at RT to give [(PN(H)P)PdH](+) (1) and [(PN(H)P)PdBCat](+) (4). Notably, 4 and 2 are isomers, but they do not interconvert even under thermolysis at 90 °C. The Pd-B bond in 4 can be further hydrolyzed more slowly, to give 1. On the other hand, a Pd-B bond was formed from the Pd-H bond in 2 by reaction with excess CatBH (and evolution of H(2)), producing 3.