Manganese-Catalyzed Electrochemical Deconstructive Chlorination of Cycloalkanols via Alkoxy Radicals
作者:Benjamin D. W. Allen、Mishra Deepak Hareram、Alex C. Seastram、Tom McBride、Thomas Wirth、Duncan L. Browne、Louis C. Morrill
DOI:10.1021/acs.orglett.9b03652
日期:2019.11.15
A manganese-catalyzedelectrochemicaldeconstructivechlorination of cycloalkanols has been developed. This electrochemical method provides access to alkoxyradicals from alcohols and exhibits a broad substrate scope, with various cyclopropanols and cyclobutanols converted into synthetically useful β- and γ-chlorinated ketones (40 examples). Furthermore, the combination of recirculating flow electrochemistry
<scp>Nickel‐Catalyzed Cross‐Coupling</scp>
of Aryl Pivalates with Cyclobutanols Involving C—O and C—C Bond Cleavage
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作者:Yi Gan、Ninghui Zhang、Shaoxu Huang、Yuanhong Liu
DOI:10.1002/cjoc.202000319
日期:2020.12
An efficient nickel‐catalyzed cross‐coupling of aryl pivalates with cyclobutanols is described. The use of Ni(cod)2/PCy3/base as the catalytic system enables the cleavage of inert C—O bond and C—Cbond under mild conditions, thus providing a facile access to γ‐arylated ketones in generally good to excellent yields. This transformation is also characterized by wide substrate scope and functional group
Photoinduced Fragmentation Borylation of Cyclic Alcohols and Hemiacetals
作者:Chao Shu、Rudrakshula Madhavachary、Adam Noble、Varinder K. Aggarwal
DOI:10.1021/acs.orglett.0c02513
日期:2020.9.18
conveniently prepared by radical-mediated ring opening of cyclic alcohols and hemiacetals, respectively. The reactions proceed under mild conditions in the absence of additives or photocatalysts, display excellent functional group tolerance, and are shown to allow cleavage of 4-, 5-, 6-, and 7-membered ring substrates. The mechanism proceeds via sequential homolytic N–O and C–C bond cleavages, the latter
Alkylation-annulation of halo esters with organometallic reagent/SmI2 couple leading to cycloalkanols: A facile cyclopropanol synthesis from a 3-halo ester
Transformation of a 3-haloester to cyclopropanols has been accomplished in excellent yields under mild conditions employing a coupled reagent of samarium(II) diiodide with organometallic reagents. 5- and 6- Haloesters were also transformed into cyclopentanols and cyclohexanols, respectively, in low to moderate yields. The reaction with a 4-halo ester gave 2,2-disubstituted tetrahydrofuran as a major
Intermolecular Oxidative Radical Addition to Aromatic Aldehydes: Direct Access to 1,4- and 1,5-Diketones via Silver-Catalyzed Ring-Opening Acylation of Cyclopropanols and Cyclobutanols
described. The reaction proceeds under mild and neutral conditions and provides a facile access to nonsymmetric 1,4- and 1,5-diketones in promising yields with broad substrate scope. Mechanistic studies including DFT calculations suggest the involvement of an uncommon water-assisted 1,2-HAT process, which is strongly exothermic and thus promotes addition of carbon radicals to aldehydes. In contrast to