Dynamic multiligand catalysis: A polar to radical crossover strategy expands alkyne carboboration to unactivated secondary alkyl halides
作者:Shin-Ho Kim-Lee、Pablo Mauleón、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1016/j.chempr.2021.06.002
日期:2021.8
triggers cooperative polar/radical pathways in a single catalytic cycle. This strategy has been applied to address a restricting limitation inherent to Cu-catalyzed B2pin2-carboboration of alkynes—the very low reactivity of the intermediate vinyl-Cu(I) species, which renders conventional methods ineffective with alkyl electrophiles other than simple primary halides. The crossover strategy enabled by
我们描述了基于前所未有的动态多配体配位池的 Cu 催化的双重策略,该池在单个催化循环中触发合作的极性/自由基途径。该策略已被应用于解决 Cu 催化的 B 2 pin 2固有的限制性限制-炔烃的碳硼化——中间体乙烯基-Cu(I) 物质的反应性非常低,这使得传统方法对烷基亲电试剂无效,而不是简单的伯卤化物。通过有机金属中间体中的配体交换实现的交叉策略克服了这一反应性问题,将碳硼化的范围扩大到未活化的仲烷基卤化物,并开辟了获得立体定义的四取代乙烯基硼酸酯的新途径。该方法具有区域选择性和立体选择性,显示出优异的官能团耐受性,并允许在任一反应伙伴处掺入复杂的碳环和杂环片段。
Direct Conversion of Internal Alkynes into α-Iodoenones: One-Step Collaborative Iodination and Oxidation
of the soft acidic noble metal catalyst and affords products featuring an additional versatile CI bond. Similar strategies for replacing ynophilic cationic gold(I) complexes in oxidative goldcatalysis with likewise ynophilic stoichiometric electrophiles would enable the development of new synthetic methods.
A highly selective hydroboration of unsymmetrical internalalkynes featuring unique regioselectivity, broad substrate scope and good functional group compatibility was realized by using cobalt catalysts modified with newly developed cyclopropane-based diphosphine ligands. The current protocol enabled the synthesis of novel alkenyl borates and improved the synthetic efficiency of bioactive compounds
Silanol–molybdenum hexacarbonyl as a new efficient catalyst for metathesis of functionalised alkynes under microwave irradiation
作者:Didier Villemin、Michael Héroux、Virginie Blot
DOI:10.1016/s0040-4039(01)00549-4
日期:2001.5
The catalytic mixture based on Mo(CO), was re-examined in the metathesis of 4-methoxytolan. Silanols (4) or (5) were found to be very active as co-catalysts. The metathesis of functional alkynes was convenient and rapidly achieved in octane as solvent under microwave irradiation in a resonance cavity. (C) 2001 Elsevier Science Ltd. All rights reserved.
VILLEMIN, D.;CADIOT, P., TETRAHEDRON LETT., 1982, 23, N 49, 5139-5140