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Please login to access the full content or check if you have access via Variation 2: From Thiiranes and Thiirane 1,1-Dioxides

DOI: 10.1055/sos-SD-047-00322

Kostikov, R. R.; Khlebnikov, A. F.; Sokolov, V. V.Science of Synthesis, (201047844.

Earlier information about the reductive desulfurization of thiiranes leading to alkenes can be found in HoubenWeyl, Vol. 5/1b, p 204, and in other sources.[‌202‌,‌290‌] This approach to alkenes has relatively rarely been used in organic synthesis because thiiranes are much less easily available starting materials than other precursors. As the most versatile methods for the preparation of thiiranes start with the treatment of the corresponding oxiranes with alkali metal thiocyanates, thioamides, or similar agents, desulfurization of thiiranes can be considered as a multistep procedure for deoxygenation of oxiranes (see Section Important precursors of sterically encumbered thiiranes (and hence alkenes) are 2,5-dihydro-1,3,4-thiadiazoles, obtained from thiocarbonyl and diazo compounds[‌291‌,‌292‌] or from carbonyl compounds, hydrazine, and hydrogen sulfide.[‌293‌] In contrast to oxiranes, for which a carbophilic attack of nucleophiles is typical, thiiranes exhibit a great tendency to thiophilic attack, leading to sulfur extrusion and thus alkene formation with retention of configuration. The classical reagents for such types of desulfurization are phosphines (e.g., to give 129 from 128) and phosphites (see also HoubenWeyl, Vol. 5/1b, p 204);[‌202‌,‌290‌‌296‌] the reduction with triphenylphosphine can be catalyzed by methyltrioxorhenium(VII)hydrogen sulfide (Table 41).[‌297‌] Alternative reagents for stereospecific desulfurization are halotrimethylsilanes (halo=Br, I),[‌298‌,‌299‌] dicarbonylchlororhodium(I) dimer,[‌300‌] and a zirconiumiridium complex (Cp)2Zr(μ-N-t-Bu)Ir(Cp*).[‌301‌] Butyllithium also reacts with a certain degree of stereoselectivity (e.g., providing 131 from 130),[‌302‌,‌303‌] whereas in the cases of tributyltin hydride,[‌304‌,‌305‌] nickelethanol, lithiumethylamine, zincacetic acid, and diphosphorus tetraiodidedimethylformamide[‌304‌] a lack of chemo- and/or stereoselectivity is observed, and the stereochemistry of desulfurizations with sodiumtoluene has not been determined.[‌306‌]

Meeee 88 Meeeeeeeeeeeeee ee Meeeeeeee[‌888‌,‌888‌,‌888‌,‌888‌,‌888‌,‌888‌,‌888‌,‌888‌]

Meeeeeee Meeeeeee Meeeeeeeee Meeeeee Meeee (%) Mee
Me8M, eeeeee, eeee, 8e 88 [‌888‌]
Me8M, MMM, eeee, eeeeeeeee 88 [‌888‌]
Me8M, 88°M, 8e 88 [‌888‌]
Me8M, 88°M, 8e 88 [‌888‌]
MeMeM8 (8eee%), M8M, MM8MM, ee, 8eee, eeee Me8M, 8eee 888 [‌888‌]
MeMeM8 (8eee%), M8M, MM8MM, ee, 8eee, eeee Me8M, 8e 888 [‌888‌]
MMMMe, MeM, ee, 8e 88e [‌888‌]
Me8Me8(MM)8 (8eee%), MM (88 × 888 Meee), eeeeeee, ee, 88e 88 [‌888‌]
MeMe, MMM/eeeeee, 88°M, 8e 88 [‌888‌]
Me8MeM, MMMM, eeeeeee, eeee, 88eee 88 [‌888‌]

e MMM eeeee.

Mee eeeeeee eeeeeeeeeee eee eeeeeeeeeeee eee eeeeeeee eee eeee eeeeeeeee eeeeeeee ee eeeeeeeee eeeeeeeeeeeee; eeeeeeeee, eee eeeeeeeee eee ee eeee eeeeeeeeeeeee ee eeee eeeeeeeeeeeee eee eeee ee eeee eee eee eeeeeeeeeee ee eeeeeee.[‌888‌,‌888‌‌888‌]

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Meeeee 88 Meeeeeeee eee Meeeeeeeeeeee ee Meeeeeee 8,8-Meeeeeee[‌888‌,‌888‌]

Meeeeeeeeeee Meeeeeeee

(M)-Meee-88-eee (888); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meee eeeeeeeeeee eeeeee ee eeeeeeeee ee e eeee-eeeeeeeeee eeee.

MMMMMMM: Meeeeeeeee, eeeeeeeee, ee eeee eeeeeeeeee ee eeeeeeeeeee eee ee eeeee.

M eeeeeee ee eee-8,8-eeeeeeeeeeeeeee (888; 8.8e, 8.8eeee), Me8M (8.8e, 8.8eeee), eee MMM (888eM) eee eeeeee eeeee eeeeee eeeee e M8 eeeeeeeeee eeeeeeeee. Mee eeeeeee eee eeeeee ee ee, eee MeM (8eM) eee eeeee. Meeeeeeeeee ee eee eeeeeee eeee e eeeee, eeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeee) ee eeeeee e eeeeeeeee eeeeee; eeeee: 8.88e (88%); MM-MM (eeee) ν̃eee: 8888, 8888, 8888, 8888, 8888, 8888, 888, 888ee-8; 8M MMM (MMMe8, δ): 8.88 (e, M=8Me, 8M), 8.88 (e, 88M), 8.88 (e, 8M), 8.88 (e, M=8.8Me, 8M).

(M)-8,8-Meeeeeee-8-eeeeeeeee-8-eee (888); Meeeeee Meeeeeeee:[‌888‌]

Me e eeee ee eeeee-8-eeee-eeeee-8-(8-eeeeeeeeeee)eeeeeeee (888; 88.8ee, 8.888eeee) ee MMM (8eM), eeeeee ee 88°M eee eeee eeeee e M8 eeeeeeeeee, eee eeeee e 8.88M eeee ee MeMe ee eeeeee (8.88eM, 8.888eeee) eeee e eeeeeee, eee eee eeeeeee eee eeeeeee eee 8e. Me eee eeeeee ee ee eeeeeeeee, eee eee eeeeeeee eee eeeeeeee eeee M8M. Mee eeeeeee eeeee eee eeeeeeeee eeee eeeeeee, eee eee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8) eee eeeeeeeeeeee. Mee eeeeeee eee eeeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, Me8M/eeeeee 8:88) ee eeee eee eeeeeee ee e eeeeee; eeeee: 88.8ee (88%); MM (eeee) ν̃eee: 8888, 8888ee-8; 8M MMM (MMMe8, δ): 8.88 (e, 8M), 8.88 (e, 8M), 8.88 (ee, M=8.8, 8.8Me, 8M), 8.88 (ee, M=88.8, 8.8Me, 8M), 8.88 (e, M=88.8Me, 8M), 8.888.88 (e, 8M).