Silenes reactions with oxygen

Absolute kinetic data have been reported for four of the characteristic bimolecular reactions of disilenes 1,2-addition of alcohols and phenols (equation 72), [2 + 2]-cycloaddition of ketones (equation 73), [2 +4]-cycloaddition of aliphatic dienes (equation 74) and oxidation with molecular oxygen (equation 75). As with silenes, the addition of alcohols has been studied in greatest detail. 

Brook and coworkers have already reported a similar reaction mode in the reaction of silene with oxygen. In that case the intermediary silanone which arises from the... 

The reaction of silenes with oxygen is exemplified by the pyrolysis of 1,1 -dimethyl-1-silacyclobutane in the presence of oxygen293, which produced several oligomers of dimethylsilanone among the products, indicating that dimethylsilanone is an intermediate. It is believed that it is formed by cycloaddition of molecular oxygen to the transient silene and a rapid decomposition of the siladioxetane to formaldehyde and dimethylsilanone (equation 188). 

Further studies of the reactions of other silenes with oxygen in argon matrices have recently been reported.212 ... 

All known silenes react violently with molecular oxygen with the exception of the stable 1-silaallenes which are air-stable. Along with carbonyl compounds the products of the oxidation of silenes are cyclic siloxanes from the corresponding silanone, depending on the reaction conditions3,8,28. For example, when the stable adamantylsilene 150 is... 

Photochemical studies of several acyldisilanes have been carried out, initially to establish whether the carbonyl oxygen of the acyldisilane would attack the a-silicon (by a 1,2-silyl shift), analogously to the acylsilanes (see the above section), with the formation of a disilyloxycarbene, or whether reaction would be with the / -silicon (a 1,3-silyl shift), by analogy with the known (but thermal) behavior of / -ketosilanes110. In the case of the acyldisilanes the result of such a 1,3-silyl shift from silicon to oxygen would be the formation of a silene (equation 70). In the experiment it was evident that both modes of... 

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