Trimethylamine oxide, bonding

A coordinate covalent bond, represented by an arrow, is one in which both electrons come from the same atom that is, the bond can be regarded as being formed by the overlap of an orbital containing two electrons with an empty one. Thus trimethylamine oxide would be represented... 

The cyclophane 35 is stable and remains unchanged upon heating to 300°C. The compound 35 is, however, readily oxidized at the Si-Si units by trimethylamine oxide in refluxing benzene, giving the cyclophane 36 containing three Si-O-Si bonds. 

Trimethylamine oxide (6, 624 7, 507) or alkaline hydrogen peroxide selectively oxidizes 2 and 3 at the C B bond to give protected 3-keto aldehydes (6). 

Similar migration of the other two R groups and hydrolysis of the B-0 bonds leads to the alcohol and boric acid. Retention of configuration is observed in R. Boranes can also be oxidized to borates in good yields with oxygen," with sodium perborate NaBOs," " and with trimethylamine oxide, either anhydrous" or in the form of the dibydrate." The reaction with oxygen is free radical in nature." ... 

Sodium permanganate and, especially, osmium tetroxide oxidize sulfoxides to sulfones but do not oxidize sulfides [837]. When a mixture of equimolar amounts of diphenyl sulfide, diphenyl sulfoxide, and osmium tetroxide is refluxed in ether for 48 h, the sulfoxide is oxidized in 96% yield to the sulfone, whereas the sulfide is completely recovered [837], Certain unsaturated sulfoxides treated with a catalytic amount of osmium tetroxide and trimethylamine oxide as a reoxidant are not only oxidized to sulfones but also hydroxylated at the double bond. The sulfoxide group exerts a steric influence in the hydroxylation two stereoisomers of a sulfoxide yield, by syn hydroxylation, two different stereoisomeric diols (equation 580) [1102]. 

Co2(CO)8 forms stable complexes with triple bonds. Trimethylamine oxide (MesNO) is used for oxidative cleavage of Co complexes. 

In general, the acetylenic triple bond is highly reactive toward hydrogenation, hydroboration, and hydration in the presence of acid catalyst. Protection of a triple bond in disubstituted acetylenic compounds is possible by complex formation with octacarbonyl dicobalt [Co2(CO)g Eq. (64) 163]. The cobalt complex that forms at ordinary temperatures is stable to reduction reactions (diborane, diimides, Grignards) and to high-temperature catalytic reactions with carbon dioxide. Regeneration of the triple bond is accomplished with ferric nitrate [164], ammonium ceric nitrate [165] or trimethylamine oxide [166]. 

Carbon monoxide insertion into an iridium-methyl bond has been reported for an >j -indenyl compound of iridium(III), Ir(/7 -C9H7)Me2(PMe3)(CO)2- In the presence of one equivalent of trimethylamine oxide, used as a carbon monoxide scavenger, carbon monoxide insertion occurs with a simultaneous increase in the hapticity of the indenyl ligand ... 

Thus, the tricarbonyliron complex 1 of myrcene reacted with dichlorocarbene via cyclopropanation of the isolated uncomplexed double bond giving 2 and no cyclopropanation product of the diene system as observed with the free ligand. Liberation of the ligand failed with trimethylamine oxide but was successful with copper(II) chloride. 

The parent TMM complex (190 R = H) undergoes photochemical ligand substitution with trifluorophosphine or trimethylamine M-oxide assisted substitution with tertiary phosphines or r-butyl isocyanide (Scheme 54). Trimethylamine -oxide assisted substitution using isoprene as the incoming ligand results in C-C bond formation to afford the bis-TT-allyl complex (197). An intramolecular version of this reaction is also known. The parent complex (190 R = H) reacts with electrophiles. Addition of HCl or Br2 gives the methallyl complexes (192) and (198), respectively. Tetrafluoroethylene adds across the Fe-C bond to afford (199) under photochemical conditions. Complex (190) undergoes Friedel-Crafts-type acylation with... 

Reaction of Alkyltrifluorosilanes with Trimethylamine Oxide. An Efficient Way of Oxidative Cleavage of the Silicon-Carbon Bonds... 

Reaction of the ferrate [Fe3(CO)n] with CI2BNR2 results in double O-borylation to furnish the di(/t3-boroxy-methylidyne) cluster, Fe3(CO)9(p3-COBClNR2)2 57 (X, Y = OB(Cl)NR2). Thermal reaction of EtSC CMe with Fe2(GO)9 in the presence of trimethylamine oxide produces the (/X3-propylidyne)(/i3-dimethylaminomethylidyne) cluster compound 57 (X= Ft, Y = NMe2) via activation of the three G-H bonds in one of the three methyl groups in the amine oxide and S-G=bond cleavage, in addition to the dinuclear complex, Fe2(GO)6(/i-SEt)2 (cf. Scheme 2). ... 

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