Boron-nitrogen compounds. 123. Preparation and reactions of bis(aminoboryl) oxides

Abstract

Bis(aminoboryl) oxides (=1,3,2-diboroxanes) of the general type [(CH 3 ) 2 N]RBOBR[N(CH 3 ) 2 ] (1a, R=N(CH 3 ) 2 ; 1b R=C 2 H 5 , 1c, R=C 6 H 5 ) have been prepared by the controlled hydrolysis of (dimethylamino)chloroboranes, (CH 3 ) 2 NBCIR. The compounds rearrange at elevated temperatures in an equilibrium reaction with the formation of boroxins, (RBO) 3 , and bis(dimethylamino)boranes, [(CH 3 ) 2 N] 2 BR. The heterocycle O(μ-C 2 H 5 BNCH 3 ) 2 BC 2 H 5 was obtained from the reaction of 1b with C 2 H 5 B(NHCH 3 ) 2 . A triply bridged species containing both three- and four-coordinate boron, RB(μ-NHCH 3 )(μ-OBRO)(μ-NCH 3 CHNCH 3 )BR, was obtained from the reaction of 1c with N-methylformamide