Synthetic Entry to Polyfunctionalized Molecules through the [3+2]-Cycloaddition of Thiocarbonyl Ylides

Article abstract of DOI:10.1021/jacs.9b07729

Here we present a comprehensive study on the [3+2]-cycloaddition of thiocarbonyl ylides with a wide variety of alkenes and alkynes. The obtained dihydro- and tetrahydrothiophene products serve as exceptionally versatile intermediates providing access to thiophenes, dienes, dendralenes, and vic-quarternary carbon centers. The use of high-pressure conditions enables thermally unstable, sterically encumbered or moderately reactive substrates to undergo the cycloaddition under mild conditions, thereby increasing the yield by up to 58percent. In addition, we showcase its utility by the formal syntheses of the pharmaceuticals NGB 4420 and tenilapine.