Carbon-13 nuclear magnetic resonance studies of carbocations. 10. Variation of cationic carbon chemical shifts with increasing electron demand in 1,1-diaryl-1-methyl (benzhydryl) carbocations
FeCl3-Catalyzed 1,2-Addition Reactions of Aryl Aldehydes with Arylboronic Acids
摘要:
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.
We report highly enantioselective dirhodium-catalyzed B−H bondinsertion reactions with diaryl diazomethanes as carbene precursors. These reactions afforded chiral gem-diarylmethine borane compounds in high yield (up to 99 % yield), high activity (turnover numbers up to 14 300), high enantioselectivity (up to 99 % ee) and showed unprecedented broad functional group tolerance.
Directing Group‐Free Formal Suzuki–Miyaura Coupling of Simple Ketones Enabled by Activation of Unstrained C−C Bonds
作者:Jiangkun Huang、Xufei Yan、Ying Xia
DOI:10.1002/anie.202211080
日期:2022.12.5
A Rh-catalyzed directing group-free formal Suzuki–Miyauracouplingreaction was established between simple ketones and arylboronates based on activation of unstrained C−C bonds. The key to the success of this reaction is a nucleophilic addition/β-carbon elimination sequence that can activate the unstrained ketone carbonyl C−C bond without the assistance of directinggroup.