Zur Reaktion von Trialkylphosphiten mit dem Titanocen-Komplex des 4,5-Dimercapto-1,3-dithiol-2-ons / Reaction of Trialkyl Phosphites with the Titanocene Complex of 4,5-Dimercapto-1,3-dithiole-2-one

Abstract

The titanocene complex 1b reacts with triethyl and trimethyl phosphite to yield the phosphonoesters 3a,b, which exist in solution as a mixture of two interconvertable conformers. The titanocene complex la is alkylated by trimethyloxonium tetrafluoroborate to form the 1,3-dithiolium tetrafluoroborate 10. The latter interacts with 9 (the lithium salt of 3a) merely by proton transfer restoring 3a. 9 condenses with aldehydes and ketones in a Horner- Wadsworth-Emmons reaction to give the titanocene complexes 16 as main products and the 4.5-bis(ethylthio)-1,3-dithiole-2-ylidene compounds 17 as byproducts.