Straightforward Access to Terminally Disubstituted Electron‐Deficient Alkylidene Cyclopent‐2‐en‐4‐ones through Olefination with α‐Carbonyl and α‐Cyano Secondary Alkyl Sulfones
作者:Lena Trifonov、Ayelet Rothstein、Edward E. Korshin、Olga Viskind、Michal Afri、Gregory Leitus、Krzysztof Palczewski、Arie Gruzman
DOI:10.1002/ejoc.202101258
日期:2021.12.28
A straightforward synthesis of virtually unexplored terminally disubstituted electron-deficient alkylidene cyclopent-2-en-4-ones was elaborated using activated secondary sulfones as alkylidene anion-radical synthons. The presented olefination process is proposed to rely on a base-promoted tandem or sequential Michael addition of C-nucleophiles to 4-acyl- or 4-silyloxycyclopent-2-en-1-ones followed
Catalytic asymmetric Mannich-type reactions of α-cyano α-sulfonyl carbanions
作者:Kohsuke Ohmatsu、Ayano Goto、Takashi Ooi
DOI:10.1039/c2cc32398b
日期:——
An efficient asymmetricMannich-typereaction of alpha-cyano alpha-sulfonyl carbanions has been achieved by exploiting the structural modularity and anion-recognition ability of chiral 1,2,3-triazolium ions. This protocol has proven to be applicable to a variety of N-Boc imines and cyanosulfones, affording beta-amino alpha-cyanosulfones in excellent yields with high stereoselectivities.
A method of treating an aqueous or non-aqueous dfsystem is disclosed which comprises adding to the system a thiolan of the formula
wherein each of X and Y, which may be the same or different, represents fluorine, chlorine or bromine, in combination with a sulphone of the formula:
R₁ - SO₂ CH = - R₂
in which R₁ represents an optionally halogenated alkyl radical or an optionally subsituted aryl radical, R₂ represents a cyano of amidocarbonyl radical and X represents a halogen atom.