N′‐tetramethylethylenediamine) or InCl3 (0.33 equiv) with [Li(tmp)] (tmp=2,2,6,6‐tetramethylpiperidino; 1.5 or 1.3 equiv, respectively) were compared with the previously described mixture of ZnCl2⋅TMEDA (0.5 equiv) and [Li(tmp)] (1.5 equiv) for their ability to deprotonate anisole, benzothiazole, and pyrimidine. [(tmp)3CdLi] proved to be the best base when used in tetrahydrofuran at room temperature, as demonstrated
Deprotonative Metalation of Substituted Benzenes and Heteroaromatics Using Amino/Alkyl Mixed Lithium-Zinc Combinations
作者:Katia Snégaroff、Shinsuke Komagawa、Floris Chevallier、Philippe C. Gros、Stéphane Golhen、Thierry Roisnel、Masanobu Uchiyama、Florence Mongin
DOI:10.1002/chem.201000543
日期:2010.7.19
Different homoleptic and heteroleptic lithium–zinccombinations were prepared, and structural elements obtained on the basis of NMR spectroscopic experiments and DFT calculations. In light of their ability to metalate anisole, pathways were proposed to justify the synergy observed for some mixtures. The best basic mixtures were obtained either by combining ZnCl2⋅TMEDA (TMEDA=N,N,N′,N′‐tetramethylethylenediamine)
[reaction: see text] Electrochemical arylation of arenecarboxaldehydes using an iron sacrificial anode in the presence of chromium and nickel catalysts afforded the corresponding arylated secondary alcohols in moderate to good yields. The chromium and nickel salts as catalysts are obtained by oxidation of a stainless steel rod during a preelectrolysis in 7% and 3%, respectively. The process was also
FeCl<sub>3</sub>-Catalyzed 1,2-Addition Reactions of Aryl Aldehydes with Arylboronic Acids
作者:Tao Zou、Sha-Sha Pi、Jin-Heng Li
DOI:10.1021/ol802529p
日期:2009.1.15
A novel protocol for the 1,2-addition reactions of electron-deficient aryl aldehydes with arylboronic acids using an inexpensive and environmentally benign iron catalyst is reported. In the presence of FeCl3 and 2-(di-tert-butylphosphino)biphenyl, 1,2-addition reactions of various electron-deficient aryl aldehydes with arylboronic acids provided the corresponding biaryl methanols in moderate to excellent yields.
Nickel- and chromium-catalysed electrochemical coupling of aryl halides with arenecarboxaldehydes
Electrochemical arylation of arenecarboxaldehydes using a stainless steel sacrificial anode in the presence of Ni catalysts afforded the corresponding arylated secondary alcohols in good yields. (C) 1999 Elsevier Science Ltd. All rights reserved.