An Alkyne Diboration/6π-Electrocyclization Strategy for the Synthesis of Pyridine Boronic Acid Derivatives
作者:Helena Mora-Radó、Laurent Bialy、Werngard Czechtizky、María Méndez、Joseph P. A. Harrity
DOI:10.1002/anie.201601084
日期:2016.5.4
A new and efficient synthesis of pyridine‐based heteroaromatic boronic acid derivatives is reported through a novel diboration/6π‐electrocyclization strategy. This method delivers a range of functionalized heterocycles from readily available startingmaterials.
The Cyclization Reaction of Ortho-Ethynylbenzaldehyde Derivatives into Isoquinoline Derivatives.
作者:Takao SAKAMOTO、Atsushi NUMATA、Yoshinori KONDO
DOI:10.1248/cpb.48.669
日期:——
In order to elucidate the reaction mechanism of the cyclization between an ethynyl group and an imino group at the ortho-position on an aromatic ring to afford isoquinolines, reaction of 2-ethynylbenzaldehydes under various conditions was examined. It is concluded that reaction proceeds via an ionic process and the isoquinoline 4-hydrogen atom derives from the solvent. In addition, it was found taht 2-ethynylbenzaldehyde O-methyloximes underwent cycliazation in the presence of primary and secondary alcohols to give 3-substituted isoquinolines.
Pd(II)-Catalyzed Tandem Heterocyclization of 1-(1-Alkynyl)cyclopropyl Oxime Derivatives for the Synthesis of Functionalized Pyrroles
作者:Dong Pan、Yin Wei、Min Shi
DOI:10.1021/acs.orglett.6b02068
日期:2016.8.5
An efficient approach for the synthesis of highly functionalized pyrroles has been developed by a Pd(TFA)2-catalyzed tandem heterocyclization of 1-(1-alkynyl)cyclopropyl oxime derivatives under mild conditions. The reaction first proceeded via an intramolecular nucleophilic attack followed by a ring-opening process and then intermolecular nucleophilic attack as well as protonation to afford the desired
A highly efficient method for the facile access of isoquinolines and isoquinoline N-oxides via a Cu(i)-catalyzed intramolecular cyclization of (E)-2-alkynylaryl oxime derivatives in water has been developed. This protocol was performed under simple and mild conditions without organic solvent, additives or ligands. By switching on/off a hydroxyl protecting group of oximes, the selective N-O/O-H cleavage