The Endocyclic Restriction Test: An Investigation of the Geometries of Thiophilic Additions of Aryl Radicals and Aryllithium Reagents to Dithioesters
摘要:
Prospective thiophilic additions of aryl radicals and aryllithium reagents in four-, six-, eight-, and 15-membered endocyclic rings have been investigated for the radical and organolithium intermediates generated from the dithioesters 8-11. These reactions, selected to provide information about the geometries of endocyclic thiophilic reactions, show radical addition to be the major pathway for all but the four-membered ring whereas endocyclic thiophilic carbanionic addition is favorable only for the eight-membered ring. The implications of these results are discussed in terms of the possible reaction mechanisms.