报道了铜催化下 α,β-不饱和砜的不同官能化。使用铜催化剂、磷酸烯丙酯、双(频哪醇)二硼和LiOMe实现了烯基砜的非对映选择性硼基化烯丙基化。在该方法中,将铜-硼基络合物添加到烯基砜中并随后进行烯丙基取代,使得硼烯丙基化产物具有良好的产率和优异的顺式非对映选择性。相反,更强的碱(KO t -Bu)通过消除磺酰基和硼基基团,进一步促进反应形成( E )-跳过的二烯。
A one-pot regioselective synthetic route to vinyl sulfones from terminal epoxides in aqueous media
作者:Ruchi Chawla、Ritu Kapoor、Atul K. Singh、Lal Dhar S. Yadav
DOI:10.1039/c2gc16664j
日期:——
A highly efficient LiBr catalysed regioselective synthesis of vinyl sulfones from readily available terminal epoxides and sodium sulfinates in a one-pot procedure using water as a reaction medium is reported. The protocol is adorned with several attributes of green chemistry like recycling of the catalyst, atom-economy and an aqueous medium.
towards phosphineoxides and phosphonates has been successfully developed through the desulfonative coupling of various sulfones with secondary phosphineoxides and phosphites. This protocol features simple experimental procedures under mild conditions (i. e., catalyst‐ and oxidant‐free, room temperature and open to air). By doing so, a variety of alkynyl, alkenyl and allyl phosphineoxides or phosphonates
Elimination and addition reactions. Part 33. Formation and behaviour of carbanions derived from sulphones and nitriles bearing β-′onium substituents
作者:Kenneth N. Barlow、Donald R. Marshall、Charles J. M. Stirling
DOI:10.1039/p29770001920
日期:——
Kinetics of eliminationreactions of β-arylsulphonylethyl- and β-cyanoethyl-ammonium and -sulphonium salts have been measured in ethanolic triethylamine buffers. The reactions show buffer saturation kinetics; at low buffer base concentrations ionisation to form the intermediate carbanion is rate-determining, but at higher buffer base concentrations the intermediate carbanion is formed in a rapidly
Visible-light-mediated alkylation of 4-alkyl-1,4-dihydropyridines with alkenyl sulfones
作者:Fuyang Yue、Jianyang Dong、Yuxiu Liu、Qingmin Wang
DOI:10.1039/d1ob01806j
日期:——
Herein we report a mild, general protocol for visible-light-mediated alkylation of 4-alkyl-1,4-dihydropyridines with alkenyl sulfones. The protocol permits efficient functionalization of sulfones with a broad range of cyclic and acyclic secondary and tertiary alkyl groups and is scalable to the gram level. Its excellent functional group tolerance and mildness make it suitable for late-stage functionalization
Visible-Light-Mediated Alkenylation of Alkyl Boronic Acids without an External Lewis Base as an Activator
作者:Fuyang Yue、Jianyang Dong、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.orglett.1c00399
日期:2021.4.2
Herein we report a protocol for the direct visible-light-mediated alkenylation of alkyl boronic acids at room temperature without an external Lewis base as an activator, and we propose a mechanism involving benzenesulfinate activation of the alkyl boronic acids. The protocol permits the efficient functionalization of a broad range of cyclic and acyclic primary and secondary alkyl boronic acids with