E. M. Shashkova

Organoboron compounds 391. Adamantyl compounds of boron

Conclusions1.We synthesized 2-(1-adamantyl)-1,3,2-dioxaborinane by carbonylation of the THF complex of 1-boraadamantane. We propose a new method for obtaining this ester by condensation of 1-bromoadamantane and 2-chlcro-1,3,2-dioxaborinane under the action of Na.2.Hydrolysis of the ester of 1-adamantylboric acid is accompanied by partial cleavage of the B- Cadam bond.3.We synthesized 1-adamantyl(dimethyl)borane by the action of MeMgI on the ester of 1-adamantylboric acid.4.On the action of various nucleophilic reagents on 1-adamantyl(dimethyl)borane, cleavage of the B-Me bond and formation of derivatives of 1-adamantyl(methyl)borane occur.

Reactions of triethylborate with amines

1. Primary and secondary amines react with thioborates to form N-substituted di-(alkylmercapto) aminoboron, alkylmercaptodiaminoboron and triaminoboron. 2. With tertiary amines the thioborates form complex compounds.

Organoboron compounds. Communication 422. Problem of bromination of 9-isopropyl-9-borabicyclo[3.3.1]nonane

Conclusions1.Bromination of i-isopropyl-9-borabicyclo[3.3.1]nonane proceeds as a radical process of substitution of the α-hydrogen atom in the isopropyl group, or with splitting of the B-Ci-Pr bond by an eleetrophilic mechanism; any one of these paths predominates, depending on the conditions.2.The formation of sec-alkyl bromides during bromination of sec-alkylborabicyclo[3.3. 1]nonanes proceeds as the result of an electrophilic halodeborylation, and not via the formation ofα-bromoalkylboranes and their proteolysis by the HBr thus liberated.

Hydroborating of dienes with chloroborane

1. Dienes (diallyl, pentadiene-1,4, butadiene-1,3) are hydroborated by chloroborane in ether solution at room temperature, the orientation of the addition being determined by the nature of the diene. 2. The reaction of chloroborane with diallyl can be used to produce 1-chloroboracycloheptane.

The synthesis of esters of alkylthioboric acids from trialkylboron and thioborates

The esters of alkylthioboric acids are obtained by heating trialkylboron with trialkylthioborates.