Selenium nucleophiles aromatic nucleophilic substitution

The migration of methyl to sulphur observed in reactions of o-mercapto-benzoic acid methyl ester with primary aliphatic amines, possibly via an S i mechanism, contributes another example to an extensive list of interactions of aromatic or/Ao-substituents. More conventional nucleophilic substitution processes include syntheses of L-selenomethionine, MeSeCH2 -CHa CH(NH2) C02H, and its c-ethyl and S e-benzyl analogues by treatment of O-toIuene-p-sulphonyl-L-homoserine with appropriate organo-selenium nucleophiles also, analogous reactions of hydroxy-acid... 

The SRN1 process has proven to be a versatile mechanism for replacing a suitable leaving group by a nucleophile at the ipso position. This reaction affords substitution in nonactivated aromatic (ArX) compounds, with an extensive variety of nucleophiles ( u ) derived from carbon, nitrogen, and oxygen to form new C—C bonds, and from tin, phosphorus, arsenic, antimony, sulfur, selenium, and tellurium to afford new C-heteroatom bonds. 

Oxygen, sulphur, selenium-substituted phenyl phthalo-nitrile ethers are prepared by the base-catalysed nucleophilic aromatic nitro displacement of 4-nitro... 

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