UNSATURATED SULFINAMIDES .16. SUBSTITUTED N-ARYL ALK-1-ENESULFINAMIDES - PREPARATION, PROPERTIES AND CONVERSION INTO THE CORRESPONDING INDOLE COMPOUNDS

Reaction of vinylic organometallic derivatives with N-sulfinyl arenami nes 2 affords the title sulfinamides 3. On heating their solutions in selected solvents to 80-124 degrees C, these sulfinamides are converte d into the corresponding indoles 6, probably via a [3.3]-sigmatropic r earrangement to intermediates VIII which undergo an intramolecular car bophilic reaction of the nitrogen atom with the neighboring sulfine gr oup, followed by elimination of HSOH. The triethyloxonium tetrafluorob orate- or boron trifluoride etherate catalyzed conversion 3 --> 6 can be carried out at a much lower temperature.