Silylamines synthesis from

A further method for the synthesis of the title compounds with only hydrogen as byproduct is the base-catalyzed dehydrogenative coupling (index D) of ammonia and tris(hydridosilylethyl)boranes, B[C2H4Si(R)H2]3 (R = H, CH3). Initially, the strong base, e.g. n-butyl lithium, deprotonates ammonia. The highly nucleophilic amide replaces a silicon-bonded hydride to form a silylamine and lithium hydride, which then deprotonates ammonia, resuming the catalytic cycle. Under the conditions used, silylamines are not stable and by elimination of ammonia, polysilazane frameworks form. In addition, compounds B[C2l-L Si(R)H2]3 can be obtained from vinylsilanes, H2C=CHSi(R)H2 (R - H, CH3), and borane dimethylsulfide. 

The insoluble pol3nner support is synthesized from silica gel and an appropriately derivatized deoxynucleoside. We routinely start with high performance liquid chromatography (HPLC) grade silica gel as a support matrix.The initial synthesis step involves refluxing 3-aminopropyl triethoxysilane with silica gel in dry toluene for 3 h to form the silylamine. This derivatized silica gel is then allowed to react with an appropriately protected nucleoside containing a 3 -p-nitrophenyl-succinate ester. The product is the nucleoside covalently linked to the support (compounds la-d). 

The DCA- and 1,4-dicyanonaphthalene (DCN)-sensitized intramolecular reactions of both acyclic and cyclic enones with acycHc and cycHc a-silylamines have been studied extensively, from both mechanistic and synthetic perspectives. - As examples (Scheme 25), DCA-sensitized irradiation of the acyclic enone 40 affords the piperidine 40a,irradiation of the y-silylaminoethylcyclohexanone 41 affords the hydroiso-quinolones 41a and 41b in a 6 1 ratio, and irradiation of the unsaturated ester 42 affords a mixture of the hydroquinoUzines 42a and 42b in a 5 1 ratio.DCA-sensitized reactions of a-silylamines have been used to synthesize key intermediates in the total synthesis of several natural products. - ... 

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