Silicon nitrogen-oxygen bonds

Fig. 11 Different compounds are formed when APTES or TESBA react with water (a) polysiloxanes produced between silicon and oxygen bonds, (b) alcohols produced between water and alkyloxy- ends or alcohols produced between water and the TESBA aldehyde end, and (c) nitrogen oxides produced between water and the APTES amine end...

Tris(trimethylsilyl)hydroxylamine heated 20 hrs. at 200 under Ng in a sealed tube methyl(trimethylsilyl)aminopentamethylsiloxane. Y almost 100%. - This is the first example of the insertion of a Si-moiety into a nitrogen-oxygen bond and also the first case in which an alkyl group is transferred from silicon to nitrogen. F. e. s. P. Boudjouk and R. West, Am. Soc. 93, 5901 (1971). 

It is believed that most of the transition metals are complexed to nitrogen donors, such as are found in amino acids or derivatives of chlorophyll, and that the metals with high ionic potentials, such as beryllium, boron, germanium, titanium, gallium, and major elements such as aluminum and silicon, may be bonded to oxygen donors of degraded lignin. 

Another modification of the double silylation process reported by Tanaka and co-workers involves the use of a bis(hydrosilane) instead of a disilane as the reactant molecule.61 This reaction can be described as a dehydrogenative double silylation, in that two Si-H bonds are activated rather than an Si-Si bond. The system is best catalyzed by Pt(CH2=CH2)(PPh3)2 other Pt, Pd, Ru, and Rh complexes give only very low yields of the double-silylated products. Alkynes, alkenes, and dienes undergo reaction with the bis (hydrosilane) with a range of results. Silicon-oxygen bonds and silicon-nitrogen bonds can also be formed by this method and are discussed in the appropriate sections later. 

TABLE 19. Derived silicon-oxygen and silicon-nitrogen bond dissociation energies (kJmol-1)a... 

Organic compounds Substances whose molecules contain one or more carbon atoms covalently bonded with another element (including hydrogen, nitrogen, oxygen, the halogens as well as phosphorus, silicon and sulfur). 

The class of phosphaalkenes with isolated P=C double bonds was first synthes ized by Becker.33 His synthetic strategy starting from trimethylsilylphosphines and acyl chlorides is still the most versatile (Protocol 3). The principle is based on the easily achievable, 1,3-silatropic migration of a silyl group bonded to phosphorus to a doubly bonded element such as nitrogen, oxygen, or sulfur. The process is favoured energetically by the construction of the P=C double bond with concomitant formation of a very stable silicon-element bond. 

---