Reactions of (CF3)(2)BNMe(2) with Grignard and related reagents. Crystal and molecular structure of (CF3)(Mes)FB-FC=NMe(2) and Ph(3)P-CH2-(CF3)(2)B-NMe(2)

Dimethylaminobis(trifluoromethyl)borane, (CF3)(2)BNMe(2) (A), reacts with Grignard reagents RMgBr to yield, after hydrolysis, the dimethylamine boranes R(CF3)(2)B . NHMe(2) (R = Me(I), Et(II), Pr-1(III), -CH2CH=CH2(IV), Ph(V), (p)Tol(VI), (o)Tol(VII), (ClC6H4)-Cl-p (VIII) and -C=CH(IX)). Alkynyltrimethylstannanes Me(3)Sn-C=C-R (R = Ph, (n)Bu) add to A across the B=N double bond and yield (R-C=C)(CF3)(2)B . NMe(2)SnMe(3), the hydrolysis of which gives (Ph-C=C)(CF3)(2)B . NHMe(2) (X) and ((n)Bu-C=C)(CF3)(2)B . NHMe(2) (XI) respectively. In contrast, mesitylmagnesiumbromide reacts with A to yield (CF3)(Mes)FB-FC=NMe(2) (XII), hydrolysis of which furnishes (CF3)(Mes)FB-C(=O)NHMe(2) (XIII). Of the phosphorus ylids, only Ph(3)P=CH2 and Ph(3)P=CHCH3 react with A to give the respective adducts Ph(3)P-CH2-(CF3)(2)B-NMe(2) (XIV) and Ph(3)P-CH(CH3)-(CF3)(2)B-NMe(2) (XV). CF3SO3CH3 alkylates XIV at the nitrogen atom to form [Ph(3)P-CH2-(CF3)(2)B-NMe(3)](+)[CF3SO3](-) (XVI). The crystal and molecular structures of XII and XIV have been determined by X-ray methods.