Increasing appendage diversity on 3,4-dihydro-3-oxo-2H-1,4-benzoxazines via Aphos–Pd(OAc)2-catalyzed Suzuki–Miyaura cross-coupling of aryl chlorides
摘要:
A library of 32 members of 3,4-dihydro-3-oxo-2H-1,4-benzoxazines has been synthesized from two substituted 2-aminophenols via microwave-assisted one-pot regioselective annulation of 2-bromoalkanoates and subsequent Suzuki-Miyaura cross-coupling of the chloro-substituted scaffolds. The latter transformation was carried out using our Aphos-Pd(OAc)(2) catalyst and the coupling of the aryl chlorides with arylboronic acids proceeded under mild reaction conditions at 60-80 degrees C in THF-H2O (10:1) in the presence of K3PO4 center dot 3H(2)O as the base to furnish the corresponding biaryl products in 80-98% yields. (C) 2013 Elsevier Ltd. All rights reserved.
Generation of an Aromatic Amide-Derived Phosphane (Aphos) Library by Self-Assisted Molecular Editing and Applications of Aphos in Room-Temperature Suzuki–Miyaura Reactions
reference Suzuki-Miyaura coupling reaction. The structures of all Aphos ligands were characterized by 31P NMR spectroscopy and their catalytic profiles in the reference reaction were evaluated by HPLC analysis. These data allowed the identification of an efficient Aphos ligand, capable of promoting room-temperature Suzuki-Miyaura coupling of unactivated and sterically hindered arylchlorides with arylboronic
Discovery of a Robust and Efficient Homogeneous Silver(I) Catalyst for the Cycloaddition of Azides onto Terminal Alkynes
作者:James McNulty、Kunal Keskar
DOI:10.1002/ejoc.201200930
日期:2012.10
A highly efficient, chemically stable, and well-defined homogeneoussilver(I) catalyst is reported for the cycloaddition of azidesontoterminalalkynes (Ag-AAC reaction). The Ag-AAC reaction occurs at room temperature or with heating to deliver exclusively the corresponding 1,4-triazole. A pronounced ligand effect was discovered through systematic modification to the ligand structure resulting in