112863-56-6Relevant academic research and scientific papers
Isomerisation of Vinyl Sulfones for the Stereoselective Synthesis of Vinyl Azides
Collins, Niall,Connon, Robert,Evans, Paul,Sánchez-Sanz, Goar
supporting information, p. 6228 - 6235 (2020/10/02)
Reported is the construction, and facile base-mediated conversation of ten differently substituted 3-azido E-vinyl sulfones (γ-azido-α,β-unsaturated sulfones) into their isomeric vinyl azide counterparts. The requisite 3-azido E-vinyl sulfones were prepared from 3-bromo E-vinyl sulfones, which in turn were accessed from allyl sulfones via a bromination-elimination sequence. In relation to this a one-pot azidation-isomerisation sequence was developed which enabled the direct formation of the vinyl azides from the corresponding 3-bromo E-vinyl sulfones. Similarly, a convenient one-pot Horner–Wadsworth–Emmons olefination-isomerisation approach was utilised in order to prepare some of the allylic sulfones used in this study. The vinyl azide forming process typically proceeded with high levels of Z-selectivity, although this was dependent on the vinyl sulfone substitution pattern. Thus, with either no substituent or a methyl group in the γ- or β-position, relative to the sulfone, good, to high levels of Z-selectivity (Z/E = 85:15 to ≥ 95:5) were obtained. However, incorporation of an α-sulfonyl methyl substituent led to an E-selective process (Z/E = 20:80). A non-bonding interaction between the azido group and the α-sulfonyl vinylic proton is proposed, which acts as a conformational control mechanism to help guide the stereochemical outcome.
Stereoselective Synthesis of Z-α,β-Unsaturated Sulfones Using Peterson Reagents
Ando, Kaori,Wada, Tomohiro,Okumura, Miho,Sumida, Hiroshi
, p. 6026 - 6029 (2016/01/09)
New Peterson reagents were prepared by introducing alkyloxy groups on the silicon atom in order to fix the conformation of the sulfone anion. The reagents 1d and 1e reacted with a variety of aldehydes after the treatment with Li-base to give Z-α,β-unsaturated sulfones with up to >99:1 selectivity in good to excellent yields. For the reaction with aliphatic aldehydes, CPME (cyclopentyl methyl ether) is the choice of solvent, while DME (1,2-dimethoxyethane) gave higher selectivity for the reaction with aromatic aldehydes.
Samarium(II) iodide-mediated deoxygenative debromination of α-bromo-β-hydroxy (acetoxy) phenyl sulfones: Synthesis of α,β-unsaturated sulfones
Reutrakul, Vichai,Jarussophon, Suwatchai,Pohmakotr, Manat,Chaiyasut, Yupa,U-Thet, Saengvimon,Tuchinda, Patoomratana
, p. 2285 - 2288 (2007/10/03)
Deoxygenative debromination of α-bromo-β-hydroxy (acetoxy) phenyl sulfones with samarium(II) iodide led to substituted α,β-unsaturated sulfones in good to excellent yields. The E-isomer is the major product. A possible mechanism via an α-sulfonyl radical pathway is proposed.
A Free Radical Addition-Fragmentation Reaction for the Preparation of Vinyl Sulfones and Phosphine Oxides
Keck, Gary E.,Byers, Jeffrey H.,Tafesh, Ahmed M.
, p. 1127 - 1128 (2007/10/02)
A free radical chain process is reported which gives vinyl sulfones or phosphine oxides in good to moderate yields under nonreducing conditions; the reaction involves irradiation of appropriate precursors to carbon-centered radicals with β-tri-n-butylstan
