sp3 C−H Bond Arylation Directed by Amidine Protecting Group: α-Arylation of Pyrrolidines and Piperidines
摘要:
A new ruthenium-catalyzed direct sp3 C-H to C-C bond transformation is disclosed. Specifically, a method for the alpha-arylation of cyclic amines, containing either permanent (pyridine, pyrimidine) or removable (amidine) directing groups, is described. This cross-coupling reaction involves heating amine substrates with arylboronate ester at 150 degrees C in a ketone solvent with a catalytic amount of ruthenium carbonyl [Ru3(CO)12]. Arylboronate esters containing either electron-withdrawing or electron-donating substituents could be efficiently coupled. Heteroarene boronates were also effective donors.
sp3 C−H Bond Arylation Directed by Amidine Protecting Group: α-Arylation of Pyrrolidines and Piperidines
摘要:
A new ruthenium-catalyzed direct sp3 C-H to C-C bond transformation is disclosed. Specifically, a method for the alpha-arylation of cyclic amines, containing either permanent (pyridine, pyrimidine) or removable (amidine) directing groups, is described. This cross-coupling reaction involves heating amine substrates with arylboronate ester at 150 degrees C in a ketone solvent with a catalytic amount of ruthenium carbonyl [Ru3(CO)12]. Arylboronate esters containing either electron-withdrawing or electron-donating substituents could be efficiently coupled. Heteroarene boronates were also effective donors.
C-2 Arylation of Piperidines through Directed Transition-Metal-Catalyzed sp<sup>3</sup>CH Activation
作者:Hana Prokopcová、Sheba D. Bergman、Karel Aelvoet、Veerle Smout、Wouter Herrebout、Benjamin Van der Veken、Lieven Meerpoel、Bert U. W. Maes
DOI:10.1002/chem.201001887
日期:2010.11.22
need is an open vial! The direct α arylation of cyclic alkylamines (see scheme) requires an open vial, as the hydrogen atom involved in the C(sp3)H‐activation process is ultimately released as hydrogen gas. Reports on the formation of hydrogen gas in direct transition‐metal‐catalyzed functionalizations are still rare. Open‐vial reactions proved crucial to this directarylation procedure as, upon sealing
The literature synthesis of 5-dialkylamino-3,4-dihydro-2H-pyrroles from 5-methoxy-3,4-dihydro-2H-pyrrole has been much improved. In initial assays, the pyrrolinium salts obtained on alkylation of the dibutylamino ami dine are excellent "naked halide" catalysts.
sp<sup>3</sup> C−H Bond Arylation Directed by Amidine Protecting Group: α-Arylation of Pyrrolidines and Piperidines
作者:Stefan J. Pastine、Denis V. Gribkov、Dalibor Sames
DOI:10.1021/ja064481j
日期:2006.11.1
A new ruthenium-catalyzed direct sp3 C-H to C-C bond transformation is disclosed. Specifically, a method for the alpha-arylation of cyclic amines, containing either permanent (pyridine, pyrimidine) or removable (amidine) directing groups, is described. This cross-coupling reaction involves heating amine substrates with arylboronate ester at 150 degrees C in a ketone solvent with a catalytic amount of ruthenium carbonyl [Ru3(CO)12]. Arylboronate esters containing either electron-withdrawing or electron-donating substituents could be efficiently coupled. Heteroarene boronates were also effective donors.