Magnesium Amide-Induced Pummerer-Type Reactions of Cyclopropyl Sulfoxides. Synthesis of Cyclopropanone Dithioacetals

Abstract

The reaction of cyclopropyl phenyl sulfoxide with a magnesium amide, generated from ethylmagnesium bromide and diisopropylamine, gave 1-(phenylthio)cyclopropanol in 72% yield. When the diisopropylmagnesium reagent was treated with a thiol prior to an interaction with cyclopropyl phenyl sulfoxides, symmetrical and unsymmetrical cyclopropanone dithioacetals were produced in fair yields along with small quantities of the corresponding 1-(phenylthio)cyclopropanols.

Intermolecular Pummerer Coupling with Carbon Nucleophiles in Non‐Electrophilic Media

“…This fast process consumes 1 and 3 and generates mixtures of alternative substrates, 1′ and 3′ , thus eroding the efficiency of the desired coupling. Inspired by earlier work by Kobayashi and co‐workers (Scheme c),– we recognized the key role of the base ( 4 ) that is required to deprotonate the sulfoxide for productive coupling (Scheme d). Bases that are too reactive produce the sulfoxide anions B ( 1 → B ), which compete with the Grignard reagents as nucleophiles in the reductive coupling, thus leading to the homodimer 5 (or various crossover dimers if 1′ is formed through S–Mg exchange).…”

Electrochemical Properties and Fluorination of Cyclopropane Derivatives Bearing Arylthio Groups

“…Trans-1-phenyl-2-phenylthiocyclopropane (1b), 35 trans-1-bromo-2-phenylthio-cyclopropane (1c), 36 methyl trans-2-phenylthiocyclopropanecarboxylate (1d), 37 1,2-diphenyl-3-phenylthiocyclopropane (1f), 38 1-phenylthio 2,2,3,3-tetramethylcyclopropane (1g), 39 1,1-bis(phenylthio)cyclopropane (1i), 40 were synthesized according to the literature methods.…”

Stereoselective Synthesis of Cyclopropanols

“…Kobayashi [78] has reported a very interesting Pummerer type reaction of cyclopropyl phenyl sulfoxide 203, leading to 1-phenylthiocyclopropanol 204 in good yield (Sheme 57). Kobayashi [78] has reported a very interesting Pummerer type reaction of cyclopropyl phenyl sulfoxide 203, leading to 1-phenylthiocyclopropanol 204 in good yield (Sheme 57).…”