A Domino Copper-Catalyzed C-N and C-O Cross-Coupling for the Conversion of Primary Amides into Oxazoles
作者:Frank Glorius、Kerstin Schuh (née Müller)
DOI:10.1055/s-2007-983782
日期:2007.7
A variety of oxazoles can efficiently be prepared, in a single step and in good yield, from primaryamides and 1,2-dihaloalkenes using copper-catalysis. This new method allows the re-gioselective formation of a range of substituted oxazoles. The required 1,2-dihaloalkenes can prepared by simple treatment of alkynes with elemental bromine or iodine.
作者:Dougal J. Ritson、Christian Spiteri、John E. Moses
DOI:10.1021/jo1025332
日期:2011.5.6
A silver-mediated one-step procedure to 2,4-disubstituted and 2,4,5-trisubstituted oxazoles has been developed. The method is complementary to existing technologies, yet provides advantages with regard to simplicity, efficiency, and performance. The silver product can be readily recycled, thus minimizing waste.
A palladium‐catalyzed tandem reaction of cyanomethyl benzoates with arylboronic acids has been achieved. Substitution at the 2‐position of cyanomethyl benzoates was found to be crucial for the selective synthesis of oxazoles and isocoumarins. Cyanomethyl benzoates afforded 2,4‐diaryloxazoles as products, while 2‐benzoyl‐substituted cyanomethyl benzoates delivered 3‐benzoyl‐4‐aryl‐isocoumarins selectively
Radical cascade synthesis of azoles <i>via</i> tandem hydrogen atom transfer
作者:Andrew D. Chen、James H. Herbort、Ethan A. Wappes、Kohki M. Nakafuku、Darsheed N. Mustafa、David A. Nagib
DOI:10.1039/c9sc06239d
日期:——
A radical cascade enables rapid, modular access to five-membered heteroarenes, including oxazoles and imidazoles, through a regio- and chemo-selective β C–H bis-functionalization.
Synthesis of 2,4-Disubstituted Oxazoles by a Copper-Catalyzed [3+2] Annulation/Olefination Cascade between Amides and IIII/PV Hybrid Ylides
作者:Zhaofeng Wang、Xingchen Ye
DOI:10.1055/a-2185-0673
日期:——
We report a novel and efficient method for oxazole synthesis through a copper-catalyzed [3+2] annulation/olefination cascade between readily available iodonium–phosphonium hybrid ylides and amides. An unprecedented α-phosphonium Cu carbenoid acts as the key intermediate. This method features excellent regioselectivity with mild reaction conditions and a broad substrate scope. Its synthetic utility