Synthesis of 2-(Trifluoromethyl)oxazoles from β-Monosubstituted Enamines via PhI(OCOCF3)2-Mediated Trifluoroacetoxylation and Cyclization
摘要:
Treatment of beta-monosubstituted enamines with phenyliodine bis(trifluoroacetate) (PIFA) was found to give a variety of 4,5-disubstituted 2-(trifluoromethyl)oxazoles. This approach allows the incorporation of the trifluoromethyl moiety in PIFA into the final products, which presumably takes place via the oxidative beta-trifluoroacetoxylation of the enamine substrates followed by subsequent intramolecular cyclization.
Solvent-Controlled Synthesis of Thiocyanated Enaminones and 2-Aminothiazoles from Enaminones, KSCN, and NBS
作者:Xiyan Duan、Xiaojing Liu、Xiaodan Cuan、Lin Wang、Kun Liu、Huiyun Zhou、Xue Chen、Huimin Li、Junqin Wang
DOI:10.1021/acs.joc.9b01722
日期:2019.10.4
and simple solvent-controlled synthesis of thiocyanated enaminones and 2-aminothiazoles has been demonstrated from enaminones, potassium thiocyanate, and N-bromosuccinimide. This process features mild reaction conditions, simple and easy operation, short reaction time, and high yield and chemoselectivity and thereby provides an efficient protocol for the divergent synthesis of thiocyanated enaminones
Substituent-Controllable Cascade Regioselective Annulation of β-Enaminones with N-Sulfonyl Triazoles for Modular Access to Imidazoles and Pyrroles
作者:Hua Wang、Tongtong Zhou、Mengdi Wu、Qingqing Ye、Xinwei He
DOI:10.3390/molecules28114416
日期:——
A controllable synthesis of trisubstitutedimidazoles and pyrroles has been developed through rhodium(II)-catalyzed regioselective annulation of N-sulfonyl-1,2,3-trizaoles with β-enaminones. The imidazole ring was formed through a 1,1-insertion of the N-H bond to α-imino rhodium carbene, followed by a subsequent intramolecular 1,4-conjugate addition. This occurred when the α-carbon atom of the amino
Synthesis of 2-Fluoroalkylated Oxazoles from β-Monosubstituted Enamines <i>via</i> Fluoroacyloxylation and Cyclization Mediated by Fluoroalkyl-Containing Hypervalent Iodine(III) Species Generated <i>In Situ</i>
作者:Zhifang Yang、Fengxia Sun、Yadong Li、Kaiyue Yang、Jianing Zhang、Lingzhi Xu、Hui Zhao、Yunfei Du
DOI:10.1021/acs.joc.3c01032
日期:2023.8.4
A metal-free synthesis of a series of fluoroalkyl-containing oxazoles from β-monosubstituted enamines was developed. This fluoroacyloxylation/cyclization cascade process was mediated by fluoroalkyl-containing hypervalent iodine(III) species formed in situ from the reaction of phenyliodine(III) diacetate (PIDA) and RCF2CO2H (R = H, Cl, Br, F, CF3, CH3, Ph, SAr, OAr).
开发了由β-单取代烯胺无金属合成一系列含氟烷基恶唑的方法。这种氟酰氧基化/环化级联过程是由二乙酸苯碘(III) (PIDA) 和 RCF 2 CO 2 H (R = H, Cl, Br, F, CF 3、CH 3、Ph、SAr、OAr)。
Chemodivergent Synthesis of Benzofurans and 2,3‐Dihydrobenzofurans via Tandem Oxidative Annulation of Enaminones and Salicylaldehydes
作者:Xiyan Duan、Hui Li、Junqi Wang、Kun Liu、Meixin Shi、Weidong Lian、Ran Chen、Pu Liu
DOI:10.1002/cjoc.202400082
日期:2024.8
and K2CO3 as promotors, controlled conditions enabled the formation of two sets of valuable heterocycles from the tandem transformation of enaminones and salicylaldehydes. The key to success was the identification of the reaction parameters, in which the imine intermediate which was formed by transient halogenation coupling and substitution processes underwent either aldolcondensation/annulation or
实现了苯并呋喃和2,3-二氢苯并呋喃的化学趋异合成。在以DBDMH和K 2 CO 3 为促进剂的反应体系下,控制条件使得烯胺酮和水杨醛串联转化形成两组有价值的杂环。成功的关键是反应参数的确定,其中通过瞬时卤化偶联和取代过程形成的亚胺中间体经历羟醛缩合/环化或亚胺水解/羟醛缩合。添加剂 NH 4 Cl 或 Fe 2 (SO 4 ) 3 控制了该反应的独特选择性。该反应中使用了广泛的烯胺酮和水杨醛底物,表现出优异的官能团耐受性和多功能性。