N-Silylamine

Substrates containing carbon nitrogen multiple bonds have received somewhat less attention. Nevertheless, imines can be converted to N-silylamines, again with RhCl3(PPh3)3 being one of the most effective catalysts (equation 10). ... 

Oximes can also be reduced to N-silylamines under similar conditions. The PdCl2 catalyzed reaction of isocyanates with triethylsilane depends on the structure (R = alkyl or aryl) of the isocyanate. Either N- or C-silylformamides can be obtained (equation 11). ... 

The hydrosilylation of imines giving N-silylamines is synthetically valuable, not only because it provides a convenient route to A-silylamines, which are known as useful reagents for organic synthesis, but also because it is a new and effective method for the reduction of imines ... 

Fluorofunctional Silylamines and -Hydrazines -Precursors of (Si-N) Ring Systems... 

Perfluoro-substituted four- and six-membered (Si-N) ring systems (3, 5) can be obtained by reacting dilithiated silylamines with SiF4. Cyclodisilazanes of the type 3 are the smallest known four-membered (Si-N) rings. Transannular Si Si ring distances of 237 pm are found [1,3]. For the first time cyclotrisilazane crystallizes in twist conformation [1]. 

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),... 

Cleavage reactions of the silicon- nitrogen bond of silylamines by TeF6 affords aminotellurium(VI) fluorides (73, 74, 76) as in Eq. (13), where n = 1, 2 ... 

Millar and Philbin have explored the nitrodesilylation of silylamines with dinitrogen pen-toxide for the synthesis of nitramines and their derivatives. These reactions, which involve nitra-tive Si-N heteroatom cleavage, are conducted in methylene chloride at subambient temperature. Trimethylsilylamines give high yields of nitramine product and reactions are clean (Table 5.8). 

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) . 

N,N-Diethyl-1,l,l-tr1methyls11ylamine SIlylamine, N,N-d1ethyl-1,1,1-trimethyl- (8) Sllanamine, N,N-d1ethyl-l,1,1-trimethyl- (9) (996-50-9)... 

Sowohl N-Trimethylsilyl-imine von Aldehyden als auch Nitrile konnen mittels Niobium-Verbindungen zu vicinalen Diaminen gekuppelt werden. Die Silylamine setzt man mit... 

Reductive-trimethylsilylation of formamides, using trimethylsilyl chloride and lithium in tetrahydrofurane lead to complex mixtures of O- and N-substituted derivatives that depend upon the conditions of the reaction and the substituents at nitrogen. However, in the presence of triethylamine, the reaction is oriented toward the unique formation of the a-silylamine. In general, the yields are moderate.185... 

Cleavage of the N-Si bond of silylamines by acyl chloride constituted a valuable approach to the corresponding amides.179... 

The influence of steric factors was thoroughly studied in the reaction of Ln(btsa)3 with the alcohol tritox-H. While the reaction takes place with larger lanthanides like neodymium to yield the homoleptic alkoxide complexes (Eq. 18) [264], the analogous reaction does not work with smaller metals like yttrium and thulium (Eq. 19). However, variation of the reaction conditions to a stoichiometric solid reaction yielded a fully exchanged product along with an unexpected and unusual silylamine degradation [265] (Eq. 20). This degradation reaction seems to be sterically forced and points out N-Si bond disruptions and C-Si bond formations under mild conditions [114]. 

A representative and interesting example for the dependency on the product s ring-size is the PET-cyclization of alkene-silylamine derivatives as described by Pandey et al. (Sch. 33) [35a]. 1,5-Cyclization (19, n= 1) predominantly gave the ds-isomer whereas the corresponding 1,6-cyclization (19, n — 2) yielded the opposite trans-isomer, respectively. Both findings were rationalized by chair-like transition states. 

The versatility of nitrogen in its compounds depends in large measure on the existence of a range of oxidation states between —3 and +5. In its combination with silicon, systems are known in which N has an oxidation state of —3 as in the derivatives of silylamines (1), of —2 as in the derivatives of silylhydrazines (2), and of —1 as in the derivatives of silylazenes (3). Whereas in these compounds silicon is tetrahedral, nitrogen has a changing coordination geometry in silylamines it is planar but in silylazenes it is linear. 

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