Synthesis of 1,3,4-Oxadiazoles by Iodine-mediated Oxidative Cyclization of Methyl Ketones with 4-Phenylsemicarbazide

Synlett ◽  
2021 ◽  
Author(s):  
Shanshan Zhang ◽  
Chuang Liu ◽  
Xiaojun Wu ◽  
Wen Li ◽  
He Li ◽  
...  

An efficient one-pot method to access 5-amino-2-benzoyl-1,3,4-oxadiazoles via I2/DMSO promoted oxidative cyclization of 4-phenylsemicarbazide with (het)aryl methyl ketones under mild conditions was developed. This reaction proceeds smoothly with a wide range of methyl ketones containing different functional groups to give the corresponding products in moderate yields under mild conditions.

Synlett ◽  
2018 ◽  
Vol 29 (14) ◽  
pp. 1926-1932
Author(s):  
Yi Liu ◽  
An-Xin Wu ◽  
Qun Cai ◽  
Hui-Yang Sheng ◽  
Deng-Kui Li

An efficient base-promoted tandem cyclization for the synthesis of polyfunctional 2-hydroxy-2,3-dihydrofurans from arylglyoxal monohydrates and 3-(1H-indol-3-yl)-3-oxopropanenitrile has been established. The investigation of the mechanism suggested that this reaction proceeds through a Knoevenagel condensation–Michael addition–oxidation–cyclization sequence. This method demonstrates the compatibility with a wide range of functional groups to produce the 2-hydroxy-2,3-dihydrofuran scaffolds in good to excellent yields in one pot.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2969
Author(s):  
Guipeng Feng ◽  
Guoyang Ma ◽  
Wenyan Chen ◽  
Shaohong Xu ◽  
Kaikai Wang ◽  
...  

[3 + 2] A 1,3-Dipolar cycloaddition of C,N-cyclic azomethine imines with allyl alkyl ketones has been achieved. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. An array of tetrahydroisoquinoline derivatives is generally constructed with good diastereoselectivities and enantioselectivities (up to >25:1 dr, >95% ee). Moreover, the absolute configuration of the product was previously determined by using the quantum electronic circular dichroism calculation and ECD spectrum method.


Synlett ◽  
2020 ◽  
Vol 31 (07) ◽  
pp. 677-682 ◽  
Author(s):  
Bin Sun ◽  
Deyu Li ◽  
Xiaohui Zhuang ◽  
Rui Zhu ◽  
Aertuke Aisha ◽  
...  

A facile protocol for visible-light-induced decarboxylative radical coupling of NHP esters with 8-aminoquinoline amides is reported, affording a highly efficient approach to synthesize a variety of 2-alkylated or 2,4-dialkylated 8-aminoquinoline derivatives. The reaction proceeds smoothly without adding any ligand, and provides the corresponding products containing a wide range of functional groups in moderate to excellent yields. This reaction uses readily available starting materials, and proceeds under mild conditions and with operational simplicity.


Synlett ◽  
2020 ◽  
Vol 31 (14) ◽  
pp. 1430-1434
Author(s):  
Ming Bian ◽  
Jin-feng Zhou ◽  
Dong-min Tang

An efficient and practical protocol for the geminal heterodihalogenation of methyl ketones by using readily available dimethyl sulfoxide and a combination of HCl and HBr is reported. Control experiments suggested that the acidity of the solution, as well as the oxidizing ability and nucleophilicity of the dimethyl sulfoxide might work cooperatively in ensuring the success of the tandem substitution. Its operational simplicity, easy accessibility, and mild oxidative conditions suggest that the present strategy might be useful for the assembly of bromochloromethyl functional groups in drug discovery.


Synthesis ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 4517-4522
Author(s):  
Li-Ping Sun ◽  
Chun-Meng Wang ◽  
Sheng-Wei Yang ◽  
Kai-Xiang Tang ◽  
Tian-Hong Gao ◽  
...  

A convenient and practical method has been developed for the synthesis of substituted oxazolo[5,4-h]pyrrolo[4,3,2-de]quinolones via the intramolecular oxidative cyclization by using PIFA as oxidant and TMSOTf as additive in DCE under an air atmosphere. The reaction proceeds in good yields and has good functional groups tolerance.


Synthesis ◽  
2019 ◽  
Vol 52 (01) ◽  
pp. 40-50 ◽  
Author(s):  
Nikita M. Chernov ◽  
Roman V. Shutov ◽  
Anastasia E. Potapova ◽  
Igor P. Yakovlev

We report an easy and powerful approach to the synthesis of novel chromeno[4,3-d]pyrimidine-5-acetic acids through ANRORC reaction of electron-deficient 3-vinylchromones and 1,3-N,N-binucleophiles. The reaction proceeds under mild conditions (EtOH, rt) and is applicable to a wide range of substrates. The described compounds show fluorescence in the violet-blue range (390–460 nm) with Stokes shift of 40–80 nm and moderate quantum yield (0.15–0.20). As the electron-withdrawing group is conserved in the form of an acetic acid fragment, these compounds may readily be functionalized or conjugated to a required substrate for (bio)analytical purposes.


Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1442-1446 ◽  
Author(s):  
Zhang-qi Lin ◽  
Chao-dong Li ◽  
Zi-chun Zhou ◽  
Shuai Xue ◽  
Jian-rong Gao ◽  
...  

A simple and highly efficient method for the preparation of tetrasubstituted NH-pyrrole from a wide range of chalcones and diethyl iminodiacetates via a Cu(OAc)2-promoted oxidation/[3+2]cycloaddition/aromatization cascade reaction has been developed. This reaction proceeds through dehydrogenations, deamination, and oxidative cyclization, affording the corresponding products in good to excellent yields. This convenient methodology for constructing tetrasubstituted NH-pyrroles has several advantages over existing methods, such as the use of easily accessible chalcones and readily available diethyl iminodiacetates, and mild reaction conditions. A wide range of substrates are tolerated.


2012 ◽  
Vol 53 (19) ◽  
pp. 2436-2439 ◽  
Author(s):  
Shao-Liang Zhang ◽  
Zhao-Feng Xue ◽  
Ya-Ru Gao ◽  
Shuai Mao ◽  
Yong-Qiang Wang

Author(s):  
Denish J. Viradiya ◽  
Vipul C. Kotadiya ◽  
Mita D. Khunt ◽  
Bharat H. Baria ◽  
Umed C. Bhoya

A green resourceful, eco-friendly and facile protocol was developed for the synthesis of benzylamine coumarin derivatives by the reaction of 4-hydroxy coumarin, secondary amine and aromatic aldehyde in the presence of PEG400 as a solvent as well as catalyst at room temperature. A wide range of functional groups were tolerated in the developed protocol. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis. The target molecules were obtained in good to excellent yield applying this method.


Synlett ◽  
2019 ◽  
Vol 30 (03) ◽  
pp. 319-324 ◽  
Author(s):  
Zhaozhan Wang ◽  
Tao Song ◽  
Yong Yang

A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.


Sign in / Sign up

Export Citation Format

Share Document