Oxidative Cyclization of Thiobenzanilides to Benzothiazoles Using N-Benzyl-DABCO Tribromide under Mild Conditions.

ChemInform ◽  
2005 ◽  
Vol 36 (46) ◽  
Author(s):  
Firouz Matloubi Moghaddam ◽  
Hassan Zali Boeini
Keyword(s):  
Oxidative Cyclization ◽  
Mild Conditions

Iron(III)/TEMPO-Catalyzed Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles by Oxidative Cyclization under Mild Conditions

Synlett ◽  
2017 ◽  
Vol 28 (11) ◽  
pp. 1373-1377 ◽  
Author(s):  
Chengrong Ding ◽  
Guofu Zhang ◽  
Yidong Yu ◽  
Yiyong Zhao ◽  
Xiaoqiang Xie
Keyword(s):  
Functional Group ◽  
Oxidative Cyclization ◽  
Mild Conditions ◽  
Broad Scope ◽  
Oxadiazole Derivatives ◽  
High Yields

A simple and efficient cationic Fe(III)/TEMPO-catalyzed oxidative cyclization of aroyl hydrazones has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazole derivatives. The reaction offers a broad scope, good functional-group tolerance, and high yields under mild conditions in the presence of O2.

scholarly journals Eosin Y-catalyzed visible-light-mediated aerobic oxidative cyclization of N,N-dimethylanilines with maleimides

2015 ◽  
Vol 11 ◽  
pp. 425-430 ◽  
Author(s):  
Zhongwei Liang ◽  
Song Xu ◽  
Wenyan Tian ◽  
Ronghua Zhang
Keyword(s):  
Visible Light ◽  
Oxidative Cyclization ◽  
Eosin Y ◽  
Efficient Synthesis ◽  
One Pot ◽  
Bond Functionalization ◽  
Metal Free ◽  
Mild Conditions ◽  
Simple Strategy ◽  
Air Atmosphere

A novel and simple strategy for the efficient synthesis of the corresponding tetrahydroquinolines from N,N-dimethylanilines and maleimides using visible light in an air atmosphere in the presence of Eosin Y as a photocatalyst has been developed. The metal-free protocol involves aerobic oxidative cyclization via sp3 C–H bond functionalization process to afford good yields in a one-pot procedure under mild conditions.

Oxidative Cyclization of Thiobenzanilides to Benzothiazoles Using N-Benzyl-DABCO Tribromide under Mild Conditions

Synlett ◽  
2005 ◽  
Vol 2005 (10) ◽  
pp. 1612-1614 ◽  
Author(s):  
Firouz Matloubi Moghaddam ◽  
Hassan Zali Boeini
Keyword(s):  
Oxidative Cyclization ◽  
Mild Conditions

Diaryloxycarbenes from oxadiazolines

2001 ◽  
Vol 79 (3) ◽  
pp. 319-327
Author(s):  
Xiaosong Lu ◽  
Darren L Reid ◽  
John Warkentin
Keyword(s):  
Acidic Solution ◽  
Benzene Solution ◽  
Subsequent Treatment ◽  
Oxidative Cyclization ◽  
Lead Tetraacetate ◽  
Dimethyl Acetylenedicarboxylate ◽  
Mild Conditions ◽  
Product Mixture ◽  
Carbonyl Ylide ◽  
Ketene Acetal

Symmetric and unsymmetric 2,2-diaryloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazolines were synthesized by oxidative cyclization of aryloxycarbonyl hydrazones of acetone with lead tetraacetate and subsequent treatment of the product mixture with a phenol in acidic solution. Thermolysis of the oxadiazolines in benzene solution at 110°C afforded carbonyl ylide intermediates that cyclize, in part, to the corresponding 2,2-diaryloxyoxirane intermediates. The oxiranes, which were not observed, are required to account for the 1,1-diaryloxy-2-methylpropenes (ketene acetals) that were isolated. Most of the carbonyl ylides fragment to acetone and diaryloxycarbenes. The latter form dimers (tetraaryloxyethenes) or they can be trapped with phenols to form orthoformates. Diphenoxycarbene was also trapped with dimethyl acetylenedicarboxylate (DMAD). The method appears to be the first for generating the parent diphenoxycarbene under relatively mild conditions in solution, and the only one to date for generating unsymmetrically substituted diaryloxycarbenes. Minor competing fragmentations of the oxadiazolines to 2-diazopropane and the appropriate diaryl carbonates, were also observed.Key words: diarylcarbonate, diaryloxycarbene, diaryloxy oxadiazoline, ketene acetal, orthoformate.

scholarly journals Efficient Synthesis and X-ray Structure of [1,2,4]Triazolo[4,3-a]pyriaadines via Oxidative Cyclization Using N-Chlorosuccinimide (NCS)

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1156
Author(s):  
Said El-Kurdi ◽  
Bassam Abu Thaher ◽  
Kanan Wahedy ◽  
Dieter Schollmeyer ◽  
Levin Nopper ◽  
...  
Keyword(s):  
Biological Activity ◽  
Oxidative Cyclization ◽  
Monoclinic Space Group ◽  
Efficient Synthesis ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Mild Conditions ◽  
Pharmaceutical Applications

Triazolopyridines are a family of compounds that, owing to their biological activity, have many pharmaceutical applications. In this study, 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine and 6-bromo-3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine were synthesized by using the chlorinated agent NCS for hydrazones under very mild conditions. The characterization of these compounds was achieved by 1H NMR, 13C NMR, FTIR, MS and X-ray diffraction. The compound 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine was crystallized in the monoclinic space group P 21/c with a = 15.1413(12), b = 6.9179(4), c = 13.0938(8) Å, β = 105.102(6)°, V = 1324.16(16)Å3, Z = 4, and R = 0.0337. Also compound 6-bromo-3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine was crystallized in the monoclinic space group P 21/c with a = 14.3213(11), b = 6.9452(4) (4), c = 12.6860(8)Å, β = 100.265(6)°, V = 1241.62(14)Å3, Z = 4, and R = 0.0561.

A Highly Efficient Heterogeneous Copper-Catalyzed Oxidative Cyclization of Benzylamines and 1,3-Dicarbonyl Compounds To Give Trisubstituted Oxazoles

Synthesis ◽  
2019 ◽  
Vol 51 (16) ◽  
pp. 3091-3100
Author(s):  
Li Wei ◽  
Shengyong You ◽  
Yuxin Tuo ◽  
Mingzhong Cai
Keyword(s):  
Copper Catalyst ◽  
Oxidative Cyclization ◽  
Dicarbonyl Compounds ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Intermolecular Cyclization ◽  
Step Procedure ◽  
Mcm 41

The heterogeneous copper-catalyzed cascade oxidative cyclization between benzylamines and 1,3-dicarbonyl compounds was achieved by using the 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized copper(II) complex [MCM-41-2N-Cu(OAc)2] as catalyst and t-BuOOH (TBHP) as oxidant, with iodine as additive, under mild conditions, yielding a wide variety of 2,4,5-trisubstituted oxazoles in mostly good to excellent yields. This heterogeneous copper catalyst can be facilely prepared via a simple two-step procedure from readily available and inexpensive reagents and exhibits a slightly higher activity than Cu(OAc)2. MCM-41-2N-Cu(OAc)2 is also easy to recover and can be recycled up to eight times with almost consistent activity. The reaction is the first example of heterogeneous copper-catalyzed intermolecular cyclization for the construction of polysubstituted oxazoles.

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 ◽  
...  
Keyword(s):  
Functional Groups ◽  
Oxidative Cyclization ◽  
Methyl Ketones ◽  
One Pot ◽  
Mild Conditions ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Aryl Methyl

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.

The Diorgano Dichalcogenides Addition to Benzyne under Mild Conditions

2007 ◽  
Author(s):  
Fabiano Toledo ◽  
Henrique Marques ◽  
João Comasseto ◽  
Cristiano Raminelli
Keyword(s):  
Mild Conditions
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