Iodine‐Promoted Synthesis of 2‐Naphthyl Thioethers from Tetralones and Sulfonyl Hydrazides

Abstract

In the traditional Bamford-Stevens-Shapiro-type reaction, electrophiles replace the carbonyl group to synthesize polysubstituted carbon-carbon double bonds. We herein report an unusually simple and general procedure to access carbon-carbon double bonds from ketones and install electrophiles at the original α-position of the carbonyl functional group, thus providing a new tool in organic synthesis. This reaction shows a wide substrate scope and functional-group tolerance.One of the classical ways to synthesize carbon-carbon double bonds from ketones is Bamford-Stevens-Shapiro reaction, [1] which involves: (1) condensation of N-sulfonyl hydrazides with ketones to afford sulfonyl hydrazones; (2) in situ generation of carbene intermediate/alkenyllithium intermediate in the presence of organolithium; and (3) trapped by electrophiles to generate corresponding alkenes (Scheme 1a). Recently, Barluen-Asian J. Org. Chem. 2019, 8, 234 -237

Recent Advances in Iodine‐Promoted C−S/N−S Bonds Formation

“…Subsequently, they reported an iodine‐mediated access to construct 2‐naphthyl thioethers 133 b from tetralones 131 b and sulfonyl hydrazides via tandem deoxygenative olefination/sulfenylation/aromatization process (Scheme 43 b). [107b] …”

Sulfonyl Hydrazides in Organic Synthesis: A Review of Recent Studies

“…The Zhou group described an I 2 ‐promoted synthesis of 2‐naphthyl thioethers from reations of sulfonyl hydrazides and tetralones (Eq. 71‐1).…”

Bamford‐Stevens and Shapiro Reactions in Organic Synthesis

“…A very unusual application of Bamford-Stevens reaction was published by Zhou. [21] He utilized Bamford-Stevens reaction for a facile preparation of 2-napthyl thioethers from tetralones and sulfonyl hydrazides (scheme 7). [21] Tetralones 37 were treated with sulfonyl hydrazides 38 in presence of catalytic iodine in chloroform at 90 °C.…”

“…A very unusual application of Bamford‐Stevens reaction was published by Zhou [21] . He utilized Bamford‐Stevens reaction for a facile preparation of 2‐napthyl thioethers from tetralones and sulfonyl hydrazides (scheme 7).…”

“…[21] He utilized Bamford-Stevens reaction for a facile preparation of 2-napthyl thioethers from tetralones and sulfonyl hydrazides (scheme 7). [21] Tetralones 37 were treated with sulfonyl hydrazides 38 in presence of catalytic iodine in chloroform at 90 °C. 2-Napthyl thioethers 39 were isolated in 40-74% yield.…”