Silylamines preparation

The second preparation for a free iminosilane was found by the Klinge-biel group. It is based on a fluorine/chlorine exchange of lithiated fluoro-silylamines with subsequent thermal LiCl elimination.17... 

Hydrosilylation of imine compounds was also an efficient method to prepare amines. The hydrosilylation product TV-silylamines can readily be desilylated upon methanol or water treatment, yielding the corresponding amines. The amines can be converted to their corresponding amides by subsequent acyl anhydride treatment. The first attempt to hydrogenate prochiral imines with Rh(I) chiral phosphine catalysts was made by Kagan102 and others. These catalysts exhibited low catalytic activity, and only moderate ee was obtained. 

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). 

Essentially all of the classical methods for the synthesis of organic amines can be successfully applied to the synthesis of a-silylamines. However, the lack of good general methods for the preparation of halomethylsilanes remains a serious drawback. 

Two examples are found for the preparation of a-silylamine derivatives by nucleophilic displacement of an oxygen functionality by an amino compound.88 96... 

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... 

A preparation of silylamines involving H2 elimination is also possible. 1,4-Disilabutane reacts with the appropriate number of equivalents of diethylamine in an alkane solvent... 

Silylamido groups are used throughout the periodic table to stabilize unusual types of bonding, coordination numbers and oxidation states. Lithium silylamides, generally prepared by reaction of the silylamine with alkyl- or aryllithium derivatives, play an important role in the synthesis of such molecules. 

In the foregoing discussion there has been no intention of minimizing the importance or the scientific interest of the remaining types of volatile covalent compounds of silicon, such as the silylamines.41 Emphasis has been placed on the hydrides, halides, and esters, only because they are more important to the present methods for preparing the organosilicon products described in later chapters. 

The apparatus and procedure employed for the preparation of (diethylamino)-tetrafluorophosphorane are identical to that described for the preparation of (dimethylamino)tetrafluorophosphorane (Sec. B). All of the precautions described in preparation B should be observed. Phosphorus pentafluoride (31.6 g, 0.25 mole) and (diethylamino)trimethylsilane (A, A -diethyl-l,l,l-trimethyl-silylamine) (0.25 mole, 36.3 g) are used. 

When 1- or 2-cyanonaphthalene is silylated, the silylamine is prepared as well as various multiple silylated naphthalene species [90]. 

Dialkyl chlorophosphites react with silylamines (80) and (82) to give the aminophosphites (81) and (83), respectively. It is also possible to prepare (84) through a similar route by removing two silyl groups. 

As with siloxanes, silylamines can be prepared by the "reamination reaction," Equation 20. 

B-Fluoroborazines have also been prepared by elimination of silyl fluorides. Facile cleavage of the Si—N bond renders silylamines very effective in the synthesis of these and other B-haloborazines, and they are extensively utilized. Reactions involving elimination of silyl halides have been found particularly useful in sterically hindered systems. ... 

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