Catalytic Boration of Alkyl Halides with Borane without Hydrodehalogenation Enabled by Titanium Catalyst
作者:Xianjin Wang、Penglei Cui、Chungu Xia、Lipeng Wu
DOI:10.1002/anie.202100569
日期:2021.5.25
titanium‐catalyzed boration of alkyl (pseudo)halides (alkyl‐X, X=I, Br, Cl, OMs) with borane (HBpin, HBcat) is reported. The use of titanium catalyst can successfully suppress the undesired hydrodehalogenation products that prevail using other transition‐metal catalysts. A series of synthetically useful alkyl boronate esters are readily obtained from various (primary, secondary, and tertiary) alkyl electrophiles,
据报道,钛与硼烷(HBpin,HBcat)形成了空前的,普通的钛催化的硼化烷基(伪)卤化物(烷基X,X = I,Br,Cl,OMs)。使用钛催化剂可以成功地抑制使用其他过渡金属催化剂时普遍存在的不希望的加氢脱卤产物。从各种(伯,仲和叔)烷基亲电试剂(包括未活化的烷基氯)可以容易地获得一系列合成上有用的烷基硼酸酯,并且对其他还原性官能团(如酯,烯烃和氨基甲酸酯)具有耐受性。对该机理的初步研究揭示了可能的自由基反应途径。我们的策略进一步扩展到芳基溴化物也得到了证明。