Carbonyl and related groups

Dimerization and polymerization can be initiated by electrophilic attack on an oxirane by a protonated or Lewis acid coordinated oxirane (Section 5.04.3.2.2). 

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Nitrogen Groups in Metal Carbonyl and Related Complexes, 10, 115 Nitrosyls, 7, 211... 

A powerful approach to the synthesis of a,p-epoxy carbonyls and related compounds is found in the Darzens reaction (Scheme 11.18b). In this context, the groups of and Arai " have investigated the asymmetric PTC-... 

Photo-Fries Rearrangement and Related Photochemical [l,j]-Shifts (j = 3,5, 7) of Carbonyl and Sulfonyl Groups... 

Molecular Rearrangements in Polynuclear Transition Metal Complexes, 16, 319 Multiply Bonded Germanium Species, 21, 241 Nitrogen Groups in Metal Carbonyl and Related Complexes, 10, 115 Nitrosyls, 7, 211... 

A/-Acyl and related groups. 1-Acylpyridinium ions are very susceptible to attack by nucleophilic reagents at the carbonyl carbon and thus are good acylating agents. They are generally encountered only as... 

The catalytic activity of zeolites in alkane to olefin reactions, photochemical conversion reactions, Fischer-Tropsch hydrogenation, isocyana-tion, carbonylation, and related chemistry make up the last theme. An important focus of this is to explore the utility of zeolites as selective heterogeneous catalysts for reactions that involve Group VIII metals. The mechanistic nature of some of this chemistry is presented, along with the characterization of supported organometallic transition metal complexes. 

The structurally related optically active a-acyl vinyl p-tolyl sulfoxide 269 underwent asymmetric cyclopropanation. Michael addition of the carbanion of bromomalonate to 269 and the subsequent intramolecular alkylation yielded the corresponding optically active a-acyl-cyclopropane 271, with a high degree of diastereoselectivity (Scheme 70).142 It was proposed that the stereochemical outcome of the reaction can be rationalized by transition state 270, in which there is chelation of the oxygen atom of the carbonyl and sulfinyl groups to the metal cation. 

The carbolithiation of alkenes and alkynes is a useful transformation for the generation of a new carbon—carbon bond, specially when the alkenes and alkynes are activated by conjugation to carbonyl and related electron-withdrawing groups. Similarly to the intramolecular carbolithiation, it is possible to carry out this reaction with high diastere-o selectivity. 

Intramolecular condensation of an active methylene with a carbonyl group and related groups... 

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