Organozinc reagents are among the most commonly used organometallicreagents in modern synthetic chemistry, and multifunctionalized organozinc reagents can be synthesized from structurally simple, readily available ones by means of alkyne carbozincation. However, this method suffers from poor tolerance for terminal alkynes, and transformation of the newly introduced organic groups is difficult, which
Differential Dihydrofunctionalization of Terminal Alkynes: Synthesis of Benzylic Alkyl Boronates through Reductive Three-Component Coupling
作者:Megan K. Armstrong、Gojko Lalic
DOI:10.1021/jacs.9b02372
日期:2019.4.17
The differential dihydrofunctionalization of terminalalkynes is accomplished through the reductive three-component coupling of terminalalkynes, aryl halides, and pinacolborane. The transformation results in hydrofunctionalization of both π-bonds of an alkyne in a single reaction promoted by cooperative action of a copper/palladium catalyst system. The differential dihydrofunctionalization reaction
favored over the binding of doxorubicin in the cavity of the cyclodextrin derivative. This contrasts with an aqueous medium in which a strong inclusion complex is formed. Cyclic voltammetry, UV–vis, 1H NMR, and molecular modeling studies of solutions in DMSO and of solutions in water/DMSO demonstrated that the two different modes of intermolecular interactionbetweendoxorubicin and the cyclodextrin derivative
β-环糊精的新合成衍生物,单(6-脱氧-6-(1-1,2,3-三唑-4-基)-1-丙烷-3-O-(4-甲氧基苯基))β-环糊精( 1)和单(6-脱氧-6硫代(1-丙烷-3-O-(4-甲氧基苯基)))β-环糊精(2)被设计为抗癌药阿霉素的受体,可以潜在地减少不良反应在治疗期间的药物。在二甲基亚砜(DMSO)水溶液和水溶液中,阿霉素与新的环糊精衍生物形成包合物,形成常数为K s = 2.3×10 4和K s = 3.2×10 5 M –1分别用于环糊精1和2。与天然β-环糊精相比,复合物的稳定性高2-3个数量级,并且环糊精侧基连接基的柔性有助于这种稳定性。在氢键接受溶剂(例如纯DMSO)中,包括氢键和氯离子的缔合比环糊精衍生物腔中阿霉素的结合更有利。这与其中形成强包合配合物的水性介质相反。循环伏安法,UV-vis,11 H NMR以及在DMSO中的溶液和在水/ DMSO中的溶液的分子模型研究表
Copper-catalyzed direct transformation of simple alkynes to alkenyl nitriles via aerobic oxidative N-incorporation
作者:Xiaoqiang Huang、Xinyao Li、Ning Jiao
DOI:10.1039/c5sc02126j
日期:——
A novel direct transformation of aliphatic terminal alkynes to alkenyl nitriles through the incorporation of a nitrogen atom into the simple hydrocarbons has been reported. The usage of inexpensive copper catalyst, O2 as the sole oxidant, broad substrate scope as well as feasibility for “late-stage modification” make this protocol very promising. Mechanistic studies including DFT calculation demonstrate
Although carbozincation of terminal alkynes is a promising method for the synthesis of alkenylzinc reagents, many challenges, especially the chemo-, regio-, and stereoselectivity, remain to be addressed. Herein we report an operationally simple, mild method for iron-catalyzed alkylzincation of terminal alkynes to produce a diverse array of alkenylzinc compounds in high yields with high anti-Markovnikov