A General Method for Suzuki–Miyaura Coupling Reactions Using Lithium Triisopropyl Borates
作者:Matthias A. Oberli、Stephen L. Buchwald
DOI:10.1021/ol302063g
日期:2012.9.7
Conditions for the Suzuki–Miyauracoupling of lithium triisopropyl borates are reported, as well as a procedure for a one-pot lithiation, borylation, and subsequent Suzuki–Miyauracoupling of various heterocycles with aryl halides. These borate species are much more stable toward protodeboronation than the corresponding boronic acids and can conveniently be stored on benchtop at room temperature.
A nickel-catalyzed decarbonylative C-H biaryl coupling of azoles and aryl esters is described. The newly developed catalytic system does not require the use of expensive metal catalysts or silver- or copper-based stoichiometric oxidants. We have successfully applied this new C-H arylation reaction to a convergent formal synthesis of muscoride A.
A Facile Synthesis of 2-Substituted Benzoxazoles
作者:Masanao Terashima、Masako Ishii、Yuichi Kanaoka
DOI:10.1055/s-1982-29847
日期:——
A green route for the synthesis of 2-substituted benzoxazole derivatives catalyzed by Al3+-exchanged K10 clay
A new, simple, and efficient protocol is developed for the synthesis of 2-substituted benzoxazole derivatives through N-C-O bond formation using Al3+-exchanged K10 clay (Al3+-K10) as catalyst. A wide range of benzoxazole derivatives are synthesized in high yields without affecting many functional groups. Hot filtration experiments showed the absence of metal leaching and catalyst can be reused for five times with only a slight decrease in yield. (C) 2013 Elsevier Ltd. All rights reserved.
Copper-catalysed intramolecular O-arylation of aryl chlorides and bromides: a straightforward approach to benzo[d]oxazoles in water
A general, efficient and more sustainable protocol for the copper-catalysed intramolecular O-arylation of o'- haloanilides leading to the benzo[d]oxazole core is reported. Remarkably, the optimised conditions allowed for the use of inexpensive and easily available aryl chlorides as arylating agents. Moreover, all reactions were carried out employing exclusively water as the solvent, rendering the methodology presented herein highly valuable from both environmental and economic points of view. (c) 2007 Elsevier Ltd. All rights reserved.