Wu Guojiao, Jacobi von Wangelin Axel
Institute of Organic Chemistry , University of Regensburg , Universitaetsstr. 31 , 93053 Regensburg , Germany.
Department of Chemistry , University of Hamburg , Martin Luther King Pl. 6 , 20146 Hamburg , Germany . Email:
Chem Sci. 2018 Jan 5;9(7):1795-1802. doi: 10.1039/c7sc04916a. eCollection 2018 Feb 21.
Stereoselective additions of highly functionalized reagents to available unsaturated hydrocarbons are an attractive synthetic tool due to their high atom economy, modularity, and rapid generation of complexity. We report efficient cobalt-catalyzed ()-halofluoroalkylations of alkynes/alkenes that enable the construction of densely functionalized, stereodefined fluorinated hydrocarbons. The mild conditions (2 mol% cat., 20 °C, acetone/water, 3 h) tolerate various functional groups, halides, alcohols, aldehydes, nitriles, esters, and heteroarenes. This reaction is the first example of a highly stereoselective cobalt-catalyzed halo-fluoroalkylation. Unlike related cobalt-catalyzed reductive couplings and Heck-type reactions, it operates a radical chain mechanism involving terminal halogen atom transfer which obviates the need for a stoichiometric sacrificial reductant.
由于其高原子经济性、模块化以及能快速生成复杂性，将高度官能化的试剂立体选择性地加成到可用的不饱和烃上是一种有吸引力的合成工具。我们报道了炔烃/烯烃的高效钴催化（）-卤氟烷基化反应，该反应能够构建官能团密集、立体构型明确的氟化烃。温和的反应条件（2 mol%催化剂，20 °C，丙酮/水，3小时）能兼容各种官能团，如卤化物、醇、醛、腈、酯和杂芳烃。该反应是高度立体选择性钴催化卤氟烷基化的首个例子。与相关的钴催化还原偶联反应和Heck型反应不同，它通过一种涉及末端卤素原子转移的自由基链机制进行，无需化学计量的牺牲性还原剂。
