Trialkylboranes, obtained via hydroboration of terminal and cyclic alkenes with BH3. SMe2, undergo redistribution with boron tribromide at room temperature under the influence of a catalytic amount (7 mol%) of BH3. SMe2 in n-pentane to afford the corresponding alkyldibromoboranes or dialkylbromoboranes, depending upon the stoichiometry, thus providing a convenient method for preparing these valuable derivatives. The reaction of ...