Enyl complexes table

A variety of the known -enyl complexes is shown in Tables 5 and 6. 

An in-depth study of platinum allyhc alkylation and subsequent comparison to ligand-identical palladium catalysts was done by Blacker et al. The aUylic alkylation of diphenyl-2-enyl acetate with dimethyl malonate, (equation 73), reveals activity for a variety of complexes with activity restricted by the source of zerovalent platinum (Table 1). Nonactive complexes are thought to be less prone to dissociation into coordinatively unsaturated catalytical active species. 

To test the validity of their assumption, Mootoo and Fraser-Reid prepared NPGs 12-18 and treated them with NBS in 1% aqueous acetonitrile [16]. Their results, summarized in O Table 1, showed that differently substituted NPGs could be chemoselectively liberated at the anomeric center to yield hemiacetals 19-24. Furthermore, benzylidene, silyl, p-methoxybenzyl (PMB), ethoxyethyl, and allyl protecting groups proved to be compatible with the conditions employed in the deprotection of the anomeric pent-4-enyl group. Diol 18, however, furnished a complex reaction mixture probably related to competing glycosylation processes, vide infra. 

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