Expedient synthesis of β,β-disubstituted α-methylenepropionates
摘要:
Baylis-Hillman alcohols are excellent sources of the allylic halides ArCH=CH(CH2X)(CO2R) (X = Br. Cl: R-1= Me, Et. Bu'). The Z double bond isomers are attained in high isomeric purity (> 14: 1. ZIE). The halides are chemo- and regiospecifically transformed into the acrylates (ArCHR2)C(=CH2)(CO2R1) on treatment with Zn(R-2)(2) (R-2 =Me. Et, CH2TMS, CH(2)SiMe(2)Ome) or PrZnBr- in the presence of catalytic amounts of copper(1) salts (0.5-20 mol%) in high yield. (C) 2004 Elsevier Ltd. All rights reserved.
Expedient synthesis of β,β-disubstituted α-methylenepropionates
摘要:
Baylis-Hillman alcohols are excellent sources of the allylic halides ArCH=CH(CH2X)(CO2R) (X = Br. Cl: R-1= Me, Et. Bu'). The Z double bond isomers are attained in high isomeric purity (> 14: 1. ZIE). The halides are chemo- and regiospecifically transformed into the acrylates (ArCHR2)C(=CH2)(CO2R1) on treatment with Zn(R-2)(2) (R-2 =Me. Et, CH2TMS, CH(2)SiMe(2)Ome) or PrZnBr- in the presence of catalytic amounts of copper(1) salts (0.5-20 mol%) in high yield. (C) 2004 Elsevier Ltd. All rights reserved.
Metal-free formal carbon–halogen bond insertion: facile syntheses of 3-halo 3,3′-disubstituted oxindoles and spirooxindole-γ-butyrolactones
作者:Rong Zhou、Rongfang Liu、Kai Zhang、Ling Han、Honghui Zhang、Wenchao Gao、Ruifeng Li
DOI:10.1039/c7cc03765a
日期:——
A novel P(NMe2)3-mediated formal carbon–halogenbond insertion of isatins into allylic and benzylic bromides/chlorides has been realized, leading to a facile synthesis of 3-halo 3,3′-disubstituted oxindoles. This reaction relies on the unique dual nucleophilic–electrophilic reactivity pattern of the Kukhtin–Ramirez adduct via a cascade SN2–SN2 process. It also represents a rare metal-free approach
已经实现了一种新型的P(NMe 2)3介导的靛红向烯丙基和苄基溴化物/氯化物的碳-卤键正式插入,从而导致了3卤代3,3'-二取代的吲哚的简便合成。该反应依赖于Kukhtin-Ramirez加合物通过级联S N 2–S N 2过程的独特的双亲核-亲电反应性模式。它还代表了一种罕见的不含金属的碳-卤素键插入方法。用三氟乙酸处理后,已从相应的插入产物中有效地制备了螺并吲哚-γ-丁内酯。