1999 organo-selenium compounds, nonmetal heterocycles

organo-selenium compounds, nonmetal heterocyclesS 0137

49 - 158Organophosphorus Compounds. Part 142. A Simple Approach to1,2,4-Selena- and Telluradiphospholes from Phosphaalkynes and theChalcogen Elements and a First Study of Their Reactivity. — Titlecompounds of type (II) and (VIII) are obtained by a new approach involving thereaction of phosphaalkynes (I) with excess selenium or tellurium. Tetracyclicproducts of type (III) are formed if phosphaalkynes (I) react with a deficit ofselenium. First investigations of the reactivity of tetracycle (III) toward triflate(IV), sulfur, selenium, and bromine result in the formation of salt (V), thioxo-and selenoxo derivatives (VI), and the novel brominated tetracycle (VII). —(ASMUS, SVEN M. F.; BERGSTRAESSER, UWE; REGITZ, MANFRED;Synthesis (1999) 9, 1642-1650; Fachbereich Chem., Univ. Kaiserslautern,D-67663 Kaiserslautern, Germany; EN)

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