secondary benzylic alcohols via tandem Ni-catalyzed cross-coupling reactions of aromatic 2-pyridyl esters with alkyl zinc reagents and carbonyl group reduction by Ni–H species is achieved. Preliminary mechanistic studies reveal that the Ni–H species is generated in situ via β-hydride elimination of the Negishi reagents. The reaction is catalyzed by bench-stable nickel salts under mild conditions with
A Phosphine-Free Manganese Catalyst Enables Stereoselective Synthesis of (1 + <i>n</i>)-Membered Cycloalkanes from Methyl Ketones and 1,<i>n</i>-Diols
作者:Akash Jana、Kuhali Das、Abhishek Kundu、Pradip Ramdas Thorve、Debashis Adhikari、Biplab Maji
DOI:10.1021/acscatal.9b05567
日期:2020.2.21
Herein, we report the stereoselective synthesis of (1 + n)-membered cycloalkane from methyl ketone and 1,n-diol. A manganese(I) complex bearing a phosphine-free ligand catalyzed the reaction, which involved the formation of two C–C bonds via a sequence of intermolecular- and intramolecular-borrowing hydrogenation reactions. It produces 2 mol of water as the sole byproduct, making the process atom economical
Herein, we describe the generation of an organochromium-type carbanion species from a non-activated C-H bond and its nucleophilic addition to aldehydes. The catalytic carbanion generation occurred through formal deprotonation of a non-activated C-H bond under mild conditions and did not need the prefunctionalization or anion stabilizing group. Carbon radical intermediates generated by decatungstate
Mechanochemistry‐Amended Barbier Reaction as an Expedient Alternative to Grignard Synthesis**
作者:Jagadeesh Varma Nallaparaju、Tatsiana Nikonovich、Tatsiana Jarg、Danylo Merzhyievskyi、Riina Aav、Dzmitry G. Kananovich
DOI:10.1002/anie.202305775
日期:2023.9.25
Use of mechanochemistry enabled the rapid in situ generation of Grignard reagents, thereby overcoming the longstanding limitations of the Magnesium-mediated Barbier reaction in solution.