Efficient synthesis of alkylboronic esters <i>via</i> magnetically recoverable copper nanoparticle-catalyzed borylation of alkyl chlorides and bromides
作者:Mahadev L. Shegavi、Abhishek Agarwal、Shubhankar Kumar Bose
DOI:10.1039/d0gc00677g
日期:——
report a magnetically separable Cu nanocatalyst (Fe-DOPA-Cu) for the borylation of alkyl halides with alkoxy diboron reagents, providing alkylboronic esters in high yields, with broad functional group tolerance under mild reaction conditions. The procedure is also applicable to the borylation of benzyl chlorides and bromides. Radical clock experiments support a radical-mediated process. Easy recycling of
A copper(II)-catalyzed borylation of alkyl halides with bis(pinacolato)diboron (B2pin2) has been developed, which can be carried out in air, providing a wide range of primary, secondary, and some tertiary alkylboronates in high yields. A variety of functional groups are tolerated and the protocol is also applicable to unactivated alkyl chlorides (including 1,1- and 1,2-dichlorides). Preliminary mechanistic
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,
iron(III) acetoacetate (Fe(acac)3) and tetramethylethylenediamine (TMEDA) enables the direct cross-coupling of alkyl halides with bis(pinacolato)diboron. This approach allows for the borylation of activated or unactivated primary, secondary, and tertiary bromides. Moreover, even the borylation of benzylic or allylic chlorides, tosylates, and mesylates are possible. The reactions proceed under mild conditions