SYNTHESIS OF SULFUR-CONTAINING HETEROCYCLES BY RING CLOSING DIENE METATHESIS

We have shown that, surprisingly, the Schrock molybdenum alkylidene ca talyst 1 can perform ring closing metathesis reactions on substrates c ontaining a sulphide group, converting diallyl sulphide 5 to 25-dihydr othiophene 6 with > 99 % conversion. By contrast, the ruthenium alkyli dene catalyst 2, which is generally more tolerant of functional groups in the substrate, is unreactive towards diallylsulphide. However even the molybdenum catalyst 1 proved unable to catalyse ring closure of t etrathiafulvalene derivative 7. Copyright (C) 1996 Elsevier Science Lt d