67082-00-2Relevant articles and documents
Unveiling the catalytic nature of palladium-N-heterocyclic carbene catalysts in the α-alkylation of ketones with primary alcohols
?etinkaya, Bekir,Ero?lu, Zafer,Gülcemal, Süleyman,Metin, ?nder,Ovezova, Mamajan
supporting information, p. 10896 - 10908 (2021/08/17)
We report herein the synthesis of four new Pd-PEPPSI complexes with backbone-modified N-heterocyclic carbene (NHC) ligands and their application as catalysts in the α-alkylation of ketones with primary alcohols using a borrowing hydrogen process and tandem Suzuki-Miyaura coupling/α-alkylation reactions. Among the synthesized Pd-PEPPSI complexes, complex2chaving 4-methoxyphenyl groups at the 4,5-positions and 4-methoxybenzyl substituents on the N-atoms of imidazole exhibited the highest catalytic activity in the α-alkylation of ketones with primary alcohols (18 examples) with yields reaching up to 95%. Additionally, complex2cwas demonstrated to be an effective catalyst for the tandem Suzuki-Miyaura-coupling/α-alkylation of ketones to give biaryl ketones with high yields. The heterogeneous nature of the present catalytic system was verified by mercury poisoning and hot filtration experiments. Moreover, the formation of NHC-stabilized Pd(0) nanoparticles during the α-alkylation reactions was identified by advanced analytical techniques.
Electrochemical-Induced Hydrogenation of Electron-Deficient Internal Olefins and Alkynes with CH3OH as Hydrogen Donor
Qin, Hongyun,Yang, Jianjing,Yan, Kelu,Xue, Yaxuan,Zhang, Meichen,Sun, Xuejun,Wen, Jiangwei,Wang, Hua
supporting information, p. 2104 - 2109 (2021/03/15)
Efficient hydrogenation of electron-deficient internal olefins and alkynes access to saturate ketone with CH3OH as a single hydrogen donor under electrochemical conditions has been successfully developed. This hydrogenation strategy can be used to convert electron-deficient internal olefins and alkynes to saturate ketone under electrochemical conditions with exogenous-reductant and a metal catalyst. Mechanistic studies reveal that radical hydrogenation was involved in this transformation. Notably, various electron-deficient internal olefins and alkynes could be tolerated in such an electrochemical hydrogenation synthetic strategy and can be easily scaled up with good efficiency. (Figure presented.).
Efficient Generation and Synthetic Applications of Alkyl-Substituted Siloxycarbenes: Suppression of Norrish-Type Fragmentations of Alkanoylsilanes by Triplet Energy Transfer
Abe, Manabu,Hagiwara, Chihiro,Ishida, Kento,Kusama, Hiroyuki,Yamazaki, Hokuto
, p. 1249 - 1253 (2020/02/04)
Acylsilanes have been known to undergo isomerization to siloxycarbenes under photoirradiation and the thus generated carbenes can be utilized for various synthetic reactions. But this carbene formation is not necessarily efficient with some alkanoylsilanes because Norrish-type fragmentations compete, which limit the synthetic utility of alkanoylsilanes as carbene precursors. In this study, generation of siloxycarbenes from alkanoylsilanes by visible-light-induced energy transfer was examined by using an Ir complex, [Ir{dF(CF3)ppy}2(dtbpy)]PF6, and was successfully applied to the C?C coupling reactions with boronic esters or aldehydes. This methodology efficiently suppressed undesired Norrish-type reactions and broadened synthetic utility of alkanoylsilanes.
