Chemodivergent Synthesis of Oxazoles and Oxime Ethers Initiated by Selective C–N/C–O Formation of Oximes and Diazo Esters
作者:Zhenjie Qi、Shaozhong Wang
DOI:10.1021/acs.orglett.1c03252
日期:2021.11.5
Chemodivergent reactions of oximes and diazo esters involving Rh-catalyzed [3+2] annulation and photodriven O–H insertion have been developed to generate oxazoles and oxime ethers. A range of aldehyde and ketone oximes reacted with α-diazocarbonyl compounds in a controllable manner in which functional groups, including ketone, ester, amide, ether, thiol ether, silane, alkene, allene, and alkyne groups
A modified Kondrat’eva cycloaddition involving an unprecedented thermally controlled metal-free decarboxylative aromatization affords an expedient access to natural 3-hydroxypyridine/piperidine systems.
Metal-Free Decarboxylative Hetero-Diels–Alder Synthesis of 3-Hydroxypyridines: A Rapid Access to <i>N</i>-Fused Bicyclic Hydroxypiperidine Scaffolds
作者:Laurie-Anne Jouanno、Vincent Di Mascio、Vincent Tognetti、Laurent Joubert、Cyrille Sabot、Pierre-Yves Renard
DOI:10.1021/jo402729a
日期:2014.2.7
A complete experimental and theoreticalstudy of the thermally controlled metal-free decarboxylative hetero-Diels–Alder (HDA) reaction of 5-alkoxyoxazoles with acrylic acid is reported. This strategy offers a new entry to valuable 2,6-difunctionalized 3-hydroxypyridines from readily available 2- and 4-disubstituted 5-alkoxyoxazoles. The reaction conditions proved compatible with, among others, ketone
New Efficient Synthesis of 5-Ethoxyoxazoles and Oxazolo[3,2-c]quinazolines via Aza-Wittig Reaction
作者:Ming-Wu Ding、Nian-Yu Huang、Yi-Bo Nie
DOI:10.1055/s-0028-1087562
日期:2009.3
5-Ethoxyoxazoles or 2-acylamino propanoates were synthesized by aza-Wittig reaction of iminophosphorane with acyl chloride in the presence of triethylamine. Reactions of 5-alkoxyoxazole with triphenyphosphine produced iminophosphoranes. A tandem aza-Wittig reaction of iminophosphorane with isocyanate or carbon disulfide generated oxazolo[3,2-c]quinazolines in satisfactory yields.
Generation of Selenoaldehydes via Retro Diels–Alder Reaction and Their Behavior in the Reaction with Some Enophiles
作者:Masahito Segi、Aojia Zhou、Mitsunori Honda
DOI:10.1080/10426500590906283
日期:2005.2.23
Abstract The [4, 2] cycloadducts of selenoaldehydes and anthracene regenerate selenoaldehydes in situ quantitatively under neutral conditions via thermal retro Diels–Alderreaction. The reactions of selenoaldehydes generated by this method with 2-silyloxy-1,3-butadiene, 2-methoxyfuran, and 5-ethoxyoxazoles are described.