Boron boranes with dimethylsulfide

The form of the polymer powder particles is maintained during pyrolysis. Nanosized Si-C-N-powder is obtained after pyrolysis. Furthermore, the high reactivity of the carbodiimide group provides an easy introduction of other elements, e.g., boron. As an example the hydroboration of bis(trimethyl-silyl)carbodiimide (4) with dimethylsulfide-borane in toluene has been investigated ... 

The method employed for the synthesis of boronated oligonucleotides is similar to the phosphoramidite method used for the synthesis of normal oligomers, except that the oxidation step has been replaced by reaction with dimethylsulfide-borane. Scheme 1. Yields have not been optimized. 

The hydroboration of dichloromethylvinylsilane in Eq. 1 was performed with borane-dimethylsulfide dissolved in toluene in a molar ratio of 3 1 at 0-10°C to exclude side reactions [7], The first and second additions take place with high a-stereoselectivity, caused by a negative partial charge at the a-C-atom [8], The third addition in Eq. 1 occurs in 3-position due to steric hindrance at boron. In order to obtain polymer 2 we added monochloroborane-dimethylsulfide in toluene to dichloromethylvinylsilane under the same reaction conditions as for 1, apart from a change in the molar ratio from 3 1 to 2 1 (Eq. 2). 

The regioselective reductive-cleavage of the galactose-glucose link in die sialic acid containing trisaccharide derivative 7 with borane-dimethylsulfide complex in the presence of boron trifluoride or by triethylsilane afforded anhydro derivative 8."... 

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