Suzuki–Miyaura Cross-Coupling of <i>N</i>-Acylpyrroles and Pyrazoles: Planar, Electronically Activated Amides in Catalytic N–C Cleavage
作者:Guangrong Meng、Roman Szostak、Michal Szostak
DOI:10.1021/acs.orglett.7b01575
日期:2017.7.7
The formation of C–C bonds from amides by catalytic activation of the amide bond has been thus far possible by steric distortion. Herein, we report the first example of a general Pd-catalyzed Suzuki–Miyaura cross-coupling of planar amides enabled by the combination of (i) electronic-activation of the amide nitrogen in N-acylpyrroles and pyrazoles and (ii) the use of a versatile Pd-NHC catalysis platform
Palladium-catalyzed Suzuki–Miyaura coupling of amides by carbon–nitrogen cleavage: general strategy for amide N–C bond activation
作者:Guangrong Meng、Michal Szostak
DOI:10.1039/c6ob00084c
日期:——
limitations are presented in the synthesis of >60 functionalized ketones. Mechanistic studies provide insight into the catalytic cycle of the cross-coupling, including the first experimental evidence for Pd insertion into the amide N–C bond. The synthetic utility is showcased by a gram-scale cross-coupling and cross-coupling at room temperature. Most importantly, this process provides a blueprint for the
General Olefin Synthesis by the Palladium‐Catalyzed Heck Reaction of Amides: Sterically Controlled Chemoselective NC Activation
作者:Guangrong Meng、Michal Szostak
DOI:10.1002/anie.201507776
日期:2015.11.23
Metal‐catalyzed reactions of amides proceeding via metal insertion into the NCO bond are severely underdeveloped due to resonance stabilization of the amide bond. Herein we report the first Heck reaction of amides proceeding via highly chemoselective NCO cleavage catalyzed by Pd0 utilizing amide bond ground‐state destabilization. Conceptually, this transformation provides access to a myriad of metal‐catalyzed
Polystyrene-supported GaCl3 as a highly efficient and recyclable heterogeneous Lewis acid catalyst for one-pot synthesis of N-substituted pyrroles
作者:Ali Rahmatpour
DOI:10.1016/j.jorganchem.2012.03.025
日期:2012.8
of N-substituted pyrroles from one-pot condensation reaction of 2,5-hexanedione with amines and diamines in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highlyactive and reusableheterogeneous Lewis acid catalyst is presented. This new protocol has the advantages of easy availability, stability, reusability and eco-friendly of the catalyst, high to excellent yields, simple
hexadehydro-Diels–Alder (HDDA) cycloisomerization reaction to produce reactive benzyne derivatives can be initiated photochemically. As with the thermal variant of the HDDA process, the reactive intermediates are formed in the absence of reagents or the resulting byproducts required for the generation of benzynes by traditional methods. This photo-HDDA (or hν-HDDA) reaction occurs at much lower temperatures (including