Dual role of allylsamarium bromide as a Grignard reagent and a single electron transfer reagent in the one-pot synthesis of terminal olefins
作者:Ying Li、Yuan-Yuan Hu、Song-Lin Zhang
DOI:10.1039/c3cc45611k
日期:——
The utility of allylsamarium bromide, both as a nucleophilic reagent and a single-electron transfer reagent, in the reaction of carbonyl compounds with allylsamarium bromide in the presence of diethyl phosphate is reported in this communication. From a synthetic point of view, a simple one-pot method for the preparation of terminal olefins is developed.
Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
作者:Dianhu Zhu、Leiyang Lv、Chen-Chen Li、Sosthene Ung、Jian Gao、Chao-Jun Li
DOI:10.1002/anie.201809112
日期:2018.12.10
carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo‐ and regioselective direct palladium‐catalyzed C‐allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallicreagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not
Amine-Activated Iron Catalysis: Air- and Moisture-Stable Alkene and Alkyne Hydrofunctionalization
作者:Amy J. Challinor、Marc Calin、Gary S. Nichol、Neil B. Carter、Stephen P. Thomas
DOI:10.1002/adsc.201600570
日期:2016.7.28
an air‐ and moisture‐stable iron(II) pre‐catalyst for alkene and alkyne hydrofunctionalization reactions. This amine activation has enabled the highly operationally simple hydrosilylation and hydroboration of alkenes and alkynes using just 0.25–2 mol% iron catalyst and 1–25 mol% amine. Significantly, these reactions proceed in equal yield under both air and inert reaction conditions.
Rational Design of a Second Generation Catalyst for Preparation of Allylsilanes Using the Silyl-Heck Reaction
作者:Jesse R. McAtee、Glenn P. A. Yap、Donald A. Watson
DOI:10.1021/ja505446y
日期:2014.7.16
second-generation ligand, bis(3,5-di-tert-butylphenyl)(tert-butyl)phosphine, for the preparation of allylsilanes using the palladium-catalyzed silyl-Heck reaction. This new ligand provides nearly complete suppression of starting material alkene isomerization that was observed with our first-generation catalyst, providing vastly improved yields of allylsilanes from simple alkene starting materials.
使用合理的配体设计,我们开发了第二代配体,双(3,5-二叔丁基苯基)(叔丁基)膦,用于使用钯催化的甲硅烷基-Heck 反应制备烯丙基硅烷。这种新的配体几乎完全抑制了我们的第一代催化剂所观察到的原料烯烃异构化,大大提高了从简单烯烃原料中获得的烯丙基硅烷的产率。描述了量化新配体的电子和空间特性的研究。最后,我们报告了使用类似配体氧化加成 Me3SiI 产生的钯络合物的 X 射线晶体结构,该结构提供了对催化系统性质的重要洞察。
Copper-Catalyzed Dicarbofunctionalization of Unactivated Olefins by Tandem Cyclization/Cross-Coupling
作者:Surendra Thapa、Prakash Basnet、Ramesh Giri
DOI:10.1021/jacs.7b01922
日期:2017.4.26
We present a strategy that difunctionalizes unactivated olefins in 1,2-positions with two carbon-based entities. This method utilizes alkyl/arylzinc reagents derived from olefin-tethered alkyl/aryl halides that undergo radical cyclization to generate C(sp3)-Cu complexes in situ, which are intercepted with aryl and heteroaryl iodides. A variety of (arylmethyl)carbo- and heterocycles (N, O) can be synthesized