Boron‐Oxygen Bond Cleavage of Pinacolborane and Catecholborane Mediated by a Scandium Phosphinidene Complex

Abstract

Abstract Reactions of bis‐scandium bridged phosphinidene complex, [LSc( μ ‐PAr)] 2 (L=MeC(NDIPP)CHC(Me)(N‐CH 2 CH 2 N( i Pr) 2 ), DIPP=2,6‐( i Pr) 2 C 6 H 3 ; Ar=2,6‐Me 2 C 6 H 3 ) ( 1 ), with pinacolborane, catecholborane, and 9‐borabicyclo[3.3.1]nonane (9‐BBN) are reported. Complex 1 reacts with pinacolborane and catecholborane to give scandium pinacolate ( 2 ) and catecholate ( 3 ), showing BO bond cleavage. These two scandium complexes contain an unusual [P(Ar)B(H)P(Ar)] 2− dianion, which displays a μ ‐ η 2 : η 2 coordination model. On the other hand, reaction of complex 1 with 9‐BBN affords the BH bond cleavage product, 1,3‐diphospha‐2,4‐diboracyclobutane ( 4 ).