19968-31-1Relevant academic research and scientific papers
Catalyst-Free Difunctionalization of Activated Alkenes in Water: Efficient Synthesis of β-Keto Sulfides and Sulfones
Wang, Huamin,Wang, Guangyu,Lu, Qingquan,Chiang, Chien-Wei,Peng, Pan,Zhou, Jiufu,Lei, Aiwen
, p. 14489 - 14493 (2016/10/03)
Difunctionalization of activated alkenes, a powerful strategy in chemical synthesis, has been accomplished for direct synthesis of a series of β-keto sulfides and β-keto sulfones. The transformation, mediated by O2, proceeds smoothly in water and without any catalyst. Prominent advantages of this method include mild reaction conditions, purification simplicity, and gram-scale synthesis, underlining the practical utility of this methodology.
Enolate Structures Contributing to the Transition State for Nucleophilic Substitution on α-Substituted Carbonyl Compounds
Yousaf, T. I.,Lewis, E. S.
, p. 6137 - 6142 (2007/10/02)
The high SN2 reactivity of α-halocarbonyl compounds is explained by the lowering of the intrinsic barrier by a major contribution of enolate structure to the transition state.This theoretical conclusion is now shown experimentally.The evidence is as follows: (1) Change in structure of a leaving arenesulfonate ion does not change the rates of attack of benzenesulfonate ion by nearly as much as it changes the equilibrium constants.A charge on the transferring phenacyl group of -0.48 is deduced. (2) The ρ value (-3.9) for attack of substituted thiophenoxides on phenacyl bromide is much more negative than that for attack on methyl iodide (-1.8). (3) A related ρ value is found for reaction of 2,4,6-trimethylphenacyl bromide with thiophenoxides (-2.2), showing a lesser, but still large sensitivity to nucleophile structure where addition to the carbonyl is sterically forbidden.The enolate structure leaves the attacking or leaving nucleophiles with a single electron each instead of the unshared pairs.Thus, the enolate structure is emphesized if the leaving group and the nucleophile readily lose an electron.
