Martin L. Cohen -- PhD 1979

Scientific Career

Thesis Title Organoselenium Chemistry. Some Mechanistic, Synthetic and Stereochemical Considerations.
Research Summary Marty discovered an unusual (and somewhat controversial) effect: that some α-seleno and α-thio enolates alkylate on S or Se, rather than on carbon or oxygen, as is usually the case. He proved this effect by the clever experiment below, in which the intermediate S-alkylated ylide preferentially undergoes a [2,3] sigmatropic rearrangment of the previously present allyl group.

Marty also developed a new amine dealkylation process, which takes advantage of the fact that selenols are acidic enough to protonate amines in organic solvents. No corresponding dealkylation can be performed with thiols.

Papers "Selenium Stabilized Carbanions. Ylide Formation During Alkylation of Selenium and Sulfur Substituted Enolates," H. J. Reich and M. L. Cohen, J. Am. Chem. Soc. 1979, 101, 1307.

"Organoselenium Chemistry. Dealkylation of Amines with Benzeneselenol," H. J. Reich and M. L. Cohen, J. Org. Chem. 1979, 44, 3148.

"Diphenyl Diselenide and Benzeneselenenyl Chloride," H. J. Reich, M. L. Cohen, and P. D. Clark, Org. Synth. 1979, 59, 141.

Current Position Principal Research Scientist, Polymer Additives, Cytec Research & Development
Cytec Industries

For comments, additions and corrections, send e-mail to Hans J. Reich