Selenides, alkyl 2-pyridyl

Synthesis of alkenes. Terminal alkenes are formed in good yield by oxidation of primary alkyl 2-pyridyl selenides with a slight excess of H202 (equation I). The same reaction with primary alkyl phenyl selenides proceeds in much lower yield. 

The selenoxide elimination of primary alkyl 2-pyridyl selenides to give terminal alkcnes also proceeds in higher yield than the corresponding reaction with alkyl phenyl selenides.2 Example ... 

Lithiated allyl sulfides (in common with allyl sulfoxides and selenides, but in contrast with allyl ethers and allyl amine derivatives) tend to react with alkyl halides at the a position, adjacent to S.1 The best a-selectivities are obtained with lithium-coordinating S-substituents such as pyridyl (114),85 imidazolyl (115), and dimethylaminocarbonyl (116).1... 

Scheme 11. Synthesis of L-vinylglycine via the alkyl-2-pyridyl selenide [16]...

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