Iron-Catalyzed Methylation Using the Borrowing Hydrogen Approach
作者:Kurt Polidano、Benjamin D. W. Allen、Jonathan M. J. Williams、Louis C. Morrill
DOI:10.1021/acscatal.8b02158
日期:2018.7.6
developed using methanol as a C1 building block. This borrowing hydrogen approach employs a Knölker-type (cyclopentadienone)ironcarbonyl complex as catalyst (2 mol %) and exhibits a broad reaction scope. A variety of ketones, indoles, oxindoles, amines, and sulfonamides undergo mono- or dimethylation in excellent isolated yields (>60 examples, 79% average yield).
demonstrate a general and broadly applicable catalytic cross coupling of methylene ketones and secondary alcohols with a series of primaryalcohols to disubstituted branched ketones. A simple and nonprecious Fe2(CO)9 catalyst enables one-pot oxidations of both primary and secondary alcohols to a range of branched gem-bis(alkyl) ketones. A number of bond activations and formations selectively occurred in
Rhenium(I)-Catalyzed C-Methylation of Ketones, Indoles, and Arylacetonitriles Using Methanol
作者:Sujan Shee、Sabuj Kundu
DOI:10.1021/acs.joc.1c00376
日期:2021.5.7
A ReCl(CO)5/MeC(CH2PPh2)3 (L2) system was developed for the C-methylation reactions utilizing methanol and base, following the borrowing hydrogen strategy. Diverse ketones, indoles, and arylacetonitriles underwent mono- and dimethylation selectively up to 99% yield. Remarkably, tandem multiple methylations were also achieved by employing this catalytic system.
Expedient Synthesis of Ketones
<i>via</i>
<scp>
<i>N</i>
‐Heterocyclic
</scp>
Carbene/
<scp>Nickel‐Catalyzed Redox‐Economical</scp>
Coupling of Alcohols and Alkynes
<sup>†</sup>
作者:Yu‐Qing Li、Feng Li、Shi‐Liang Shi
DOI:10.1002/cjoc.202000019
日期:2020.10
N‐heterocyclic carbene/nickel‐catalyzed direct coupling of alcohols and internal alkynes to form α‐branched ketones has been developed. This methodology provides a new approach to afford branched ketones, which are difficult to access through the hydroacylation of simple internal alkenes with aldehydes. This redox‐neutral and redox‐economical coupling is free from any oxidative or reductive additives
One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through