SELECTIVE REDUCTION OF TERTIARY ALKYL, BENZYL, AND ALLYL HALIDES TO HYDROCARBONS USING LITHIUM 9,9-DI-N-BUTYL-9-BORABICYCLONONANATE

Article abstract of DOI:10.1016/S0040-4020(01)97982-7

The title 9-borabicyclo<3.3.1>nonane(9-BBN) ate complex (1) brings about selective removal of tertiary alkyl, benzyl, and allyl halides to give the corresponding hydrocarbons in excellent yields without concomitant attack on secondary, primary and aryl derivatives.The reduction of cis- and trans-4-t-butyl-1-methylcyclohexyl chlorides (2) with 1 gives 4-t-butyl-1-methylcyclohexanes (3) with partial inversion of configuration in cyclohexane, while that in benzene gives thermodynamically trans-3 predominantly.The reactions of 1,1-dimethyl-5-hexenyl chloride (4) and 1,7,7-trimethylbicyclo<2.2.1>hept-2-yl chloride (8) with 1 proceed with the rearrangements characteristic to a carbonium ion intermediate.The reduction of 1-ethyl-1-methylpentyl chloride with 1 follows a second-order rate equation.