Alkylation nitrogen-stabilized

Reacting nitrogen-stabilized a-carbenium dithioates 110 and 111 (inner salts) with electrophiles yields the a-carbenium dithioesters 112 and 113, respectively, in high yields, as shown in Scheme 23 [64] and Scheme 24 [65]. Hydrolysis of 112 and 113 gives a-oxo dithioates 114 and 115, respectively. In the case of imidazolidinium dithioate 117, prepared from the inner salt 116, the hydrolysis is followed by intramolecular cyclization to give a 28% yield of 3-thioxo piperazin-2-one 118 (Scheme 25) [64]. The alkylation of p-carbenium dithioate 119 proceeds similarly (Scheme 26) [66]. 

For instance, norbornyl anions can stabilize cobalt in the 5+ oxidation state (Co(Nor)/), /.e., a e electronic structure (in the field of Tj symmetry) (7). Nickel(I) complexes are stable when alkylated nitrogen donor atoms are incorporated into the macro ring. 

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