From Silylamines

The reaction of silylamines 9 with cyanogen chloride in diethyl ether affords mono silyl carbodiimides 10. On standing only the t-butyl and the phenyl derivatives are stable, the other derivatives rearrange to give the cyanamide isomers 11.  

In the reaction of the sodium salt of bis(trialkylsilyl)amines 12 with phosgene, 

reaction of t-butyl isocyanate with LiN(SiMc3)2 14 affords N-t-butyl-N -trimethylsilyl-carbodiimide 15 in 56% yield.  

Reaction of methyl-bis(trimethylsilyl) amine 16 with NC—N=S=0 at —70 °C gives bis-(trimethylsilyl)carbodiimide 17 in 80 % yield.  

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By comparison with IP data from silylamines, the vertical IP corresponding to a nitrogen 2p orbital in planar trimethylamine was estimated to be 11-1.9 eV40. 

Harris, J.M. et al.. Hydrogen abstraction from silylamines An investigation of the 1,2-migration of the trimethylsilyl group in aminyl radicals, J. Chem. Soc., Perkin Trans. 2, 2119, 1993. 

Apparently, amines act as Si-nucleophiles toward BENAs (434), and elimination of silylamines (Si N < ) and silanol (from hemiacetals A) affords nitroso-alkenes B as key intermediates of this process. According to the published data (503), a-nitrosoalkenes B react with amines to give the target oximes (453),... 

The acid fluoride (3 mmol), obtained from the carboxylic acid and cyanuric fluoride, and TBA-F (5 mg, 0.02 mmol) are added to the silylamine (3 mmol) in MeCN (5 ml) under N2 and the solution is stirred for 6 h at room temperature. The solvent is removed under reduced pressure and the residue is taken up in CH2Cl2. The organic solution is washed with aqueous NaHCO, (5%, 2 x 10 ml), aqueous HCI (4M, 2 x 10 ml) and H20 (20 ml), dried (Na2S04), and evaporated to yield the amide (>75%). 

The oxidation of an amine can benefit from the use of an electroauxiliary [19-28]. Electroauxiliaries are substituents that both lower the initial oxidation potential of the substrate and control the formation of the subsequent reactive intermediates. To this end, the anodic oxidation of the 6-membered ring a-silylamines in the presence of cyanide was shown to afford a net displacement of the silyl... 

The scope of nitrolysis is huge, with examples of nitramine formation from the cleavage of tertiary amines, methylenediamines, carbamates, ureas, formamides, acetamides and other amides. The deflnition of nitrolysis must be extended to the nitrative cleavage of other nitrogen bonds because sulfonamides and nitrosamines are also important substrates for these reactions. The nitrative cleavage of silylamines and silylamides is also a form of nitrolysis (Section 5.7). 

In contrast to 1,2-migrations between C and O, there are few reports on the Brook isomerization of a-silylamine (aza-Brook isomerization). The reaction of (a-silylallyl)amine 61 with n-C4H9Li in THF at low temperatnre followed by the addition of HMPA and CH3I gives the methylated prodnct 62 in qnantitative yield. These resnlts indicate that an aza-Brook isomerization occnrs, i.e. the silyl group of 61 migrates from carbon to nitrogen and the lithinm salt of an aUyl anion 63 is produced (equation 22) . 

Bis(organosilyl) peroxides are prepared by nucleophilic substitution reactions of hydrogen peroxide with chlorosilanes in the presence of base . Thus, bis(triorganosilyl) peroxide has been prepared from the reaction of 98% hydrogen peroxide and chlorosilane with ammonia as an HCl acceptor (equation 3). Bis(triphenylsilyl) peroxide 2 can also be prepared by the reaction of hydrogen peroxide and triphenyl silylamine (equation 4). 

V,/V-Dialkyl-RSMAs have been prepared by addition of silyllithium reagents to iminium salts formed in situ by reacting aldehydes with silylamines in the presence of lithium perchlorate. Although excellent yields have been obtained, except when starting from enolizable aldehydes, the use of the dangerous reagent lithium perchlorate makes this procedure less attractive.197... 

Ligands Derived from Simple Amines and Silylamines... 

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. 

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