Synthesis of 2‐Alkenyl‐4
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‐3,1‐Benzoxazin‐4‐Ones through HFIP‐Mediated Decarboxylative [4+2]‐Annulation of Isatoic Anhydrides with Cyclopropenones under Silver Catalysis
作者:Mengqi Yang、Jixin Wang、Weiwei Lv、Dan Ba、Guolin Cheng、Lianhui Wang
DOI:10.1002/adsc.202100489
日期:2021.8.13
We herein describes an HFIP-mediated [4+2]-cycloaddition reaction from simple and easily available isatoic anhydrides and cyclopropenones under silver catalysis. This transformation involves the tandem decarboxylative esterification, intermolecular addition, intramolecular substitution, small ring opening and isomerization processes, which allows the rapid assembly of versatile 2-diarylalkenyl-4H-3
我们在此描述了 HFIP 介导的 [4+2]-环加成反应,该反应在银催化下由简单易得的靛红酸酐和环丙烯酮进行。这种转化涉及串联脱羧酯化、分子间加成、分子内取代、小开环和异构化过程,这使得多功能 2-diarylalkenyl-4 H -3,1-benzoxazin-4-ones的快速组装成为可能。
Palladium-Catalyzed Synthesis of Functionalized Indoles by Acylation/Allylation of 2-Alkynylanilines with Three-Membered Rings
作者:Weiliang Yuan、Xiaojiao Li、Zisong Qi、Xingwei Li
DOI:10.1021/acs.orglett.2c00246
日期:2022.3.25
Palladium-catalyzed synthesis of 3-acyl and -allyl indoles has been realized by merging nucleophilic cyclization of ortho-alkynylanilines with ring opening of three-memberedrings such as cyclopropenones and gem-difluorinated cyclopropanes. These functionalized indoles were obtained in moderate to high yields with high stereoselectivity in both cases. This protocol provides an alternative method toward
Nickel(0)‐Catalyzed Enantioselective [3+2] Annulation of Cyclopropenones and α,β‐Unsaturated Ketones/Imines
作者:Dachang Bai、Yanjiang Yu、Haiming Guo、Junbiao Chang、Xingwei Li
DOI:10.1002/anie.201913130
日期:2020.2.10
Ni0 -catalyzed chemo- and enantioselective [3+2] cycloaddition of cyclopropenones and α,β-unsaturatedketones/imines is described. This reaction integrates C-C bond cleavage of cyclopropenones and enantioselective functionalization by carbonyl/imine group, offering a mild approach to γ-alkenyl butenolides and lactams in excellent enantioselectivity (88-98 % ee) through intermolecular C-C activation
Transition-Metal-, Additive-, and Solvent-Free [3 + 3] Annulation of RCF<sub>2</sub>-Imidoyl Sulfoxonium Ylides with Cyclopropenones to Give Multifunctionalized CF<sub>3</sub>-Pyridones
An efficient and practical strategy was developed to synthesize 1,3,4-triaryl-6-trifluoromethylpyridones from CF3-imidoyl sulfoxoniumylides and cyclopropenones in good to excellent yields. This stepwise [3 + 3] annulation reaction was carried out under transition-metal-, additive-, and solvent-free conditions, generating 1 equiv of dimethyl sulfoxide as byproduct and tolerating a series of functional
We report herein the Pd-catalyzed selective ring-opening reaction of cyclopropenones with vinyl epoxides. By using a commercially available Pd2(dba)3·CHCl3–BINAP catalyst, a wide range of conjugated alkadienyl carboxylates could be accessed in good yield and excellent regioselectivity. The new application of zwitterionic π-allyl palladium intermediates has been demonstrated in organic synthesis.