In situ generation of nitrile oxides from copper carbene and tert-butyl nitrite: synthesis of fully substituted isoxazoles

2018 ◽  
Vol 16 (25) ◽  
pp. 4683-4687 ◽  
Author(s):  
Rongxiang Chen ◽  
Abosede Adejoke Ogunlana ◽  
Shangwen Fang ◽  
Wenhao Long ◽  
Hongmei Sun ◽  
...  
Keyword(s):  
Cycloaddition Reaction ◽  
Nitrile Oxides ◽  
Tert Butyl ◽  
Keto Esters ◽  
In Situ Generation

Herein, a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite, was developed effectively to give fully substituted isoxazoles.

Organic Curing Agents for Polysulfide Sealants. II. Additions of Thiols to Nitrile Oxides: Scope, Relative Reactivities and Application to the Cure of Polysulfide Sealants

1989 ◽  
Vol 42 (8) ◽  
pp. 1257 ◽  
Author(s):  
PJ Hanhela ◽  
DB Paul
Keyword(s):  
Ambient Temperature ◽  
Elevated Temperatures ◽  
Barium Oxide ◽  
Free Products ◽  
Ambient Temperatures ◽  
Nitrile Oxides ◽  
Curing Agents ◽  
In Situ Generation ◽  
Long Chain

Efficient addition between various nitrile oxides and both short (C2) and long chain (C16) alkyl thiols , aliphatic dithiols and aryl thiols occurred rapidly at ambient temperature with the formation of thiohydroximic acid derivatives. Competitive experiments with bis( nitrile oxides) showed that for terephthalonitrile oxide the second addition proceeded more readily than the first whereas with anthracene-9,l0-bis(carbonitrile oxide) elevated temperatures were needed to obtain the diadduct. Relative reactivities of a number of thiols with nitrile oxides were also determined spectroscopically . Reaction between prop-2-ene-1-thiol and p-nitrobenzonitrile oxide afforded products resulting from both cycloaddition and 1,3-addition with the latter predominating. The polysulfide prepolymer LP-2 was cured effectively at ambient temperatures by both terephthalonitrile oxide and 4,4'-sulfonylbisbenzonitrile dioxide at CNO to SH ratios of 1.5 and higher giving tack-free products within 0.5 h and 90% cure in under 4 h. For the less highly cross-linked LP-32-based sealants, curing was a little slower. Unreinforced sealants produced in this manner were firm elastomers with hardness of 35-40 (Rex A). The naphthalenebis (carbonitrile oxides) afforded softer products while anthracene-9,10- bis(carbonitrile oxide) was ineffective. One-part formulations involving in situ generation of nitrile oxide from hydroximoyl chlorides and barium hydroxide (formed by action of water vapour on barium oxide) were also produced.

Generation of azaarene nitrile oxides from methyl azaarenes and t-BuONO enabling synthesis of furoxans and 1,2,4-oxadiazoles

2022 ◽  
Author(s):  
Xiang-Jin Zhang ◽  
Jian-Kang Cao ◽  
Jun-Jie Ren ◽  
Lin Hong ◽  
Ru-Jin Liang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Nitrogen Sources ◽  
Nitrile Oxides ◽  
Tert Butyl

A high-efficiency strategy for the synthesis of furoxans and 1,2,4-oxadiazoles has been developed, utilizing tert-butyl nitrite (TBN) as nitrogen sources. Azaarene nitrile oxides as activated intermediates were generated in-situ via...

In Situ Generation of Nitrile Oxides from NaCl–Oxone Oxidation of Various Aldoximes and Their 1,3-Dipolar Cycloaddition

2018 ◽  
Vol 21 (1) ◽  
pp. 315-319 ◽  
Author(s):  
Guodong Zhao ◽  
Lixin Liang ◽  
Chi Ho Ethan Wen ◽  
Rongbiao Tong
Keyword(s):  
Dipolar Cycloaddition ◽  
Nitrile Oxides ◽  
In Situ Generation

New method of in situ generation of nitrile oxides by MnO2 oxidation of aldoximes

1999 ◽  
Vol 40 (30) ◽  
pp. 5605-5608 ◽  
Author(s):  
Jarosław Kiegiel ◽  
Magdalena Popławska ◽  
Julita Jóźwik ◽  
Małgorzata Kosior ◽  
Janusz Jurczak
Keyword(s):  
New Method ◽  
Nitrile Oxides ◽  
In Situ Generation

ChemInform Abstract: New Method for in situ Generation of Nitrile Oxides by MnO2 Oxidation of Aldoximes.

ChemInform ◽  
2010 ◽  
Vol 30 (44) ◽  
pp. no-no
Author(s):  
Jaroslaw Kiegiel ◽  
Magdalena Poplawska ◽  
Julita Jozwik ◽  
Malgorzata Kosior ◽  
Janusz Jurczak
Keyword(s):  
New Method ◽  
Nitrile Oxides ◽  
In Situ Generation

A multinuclear NMR study of the cycloaddition reaction of SNSAsF6 with tert-butylphosphaacetyline (CH3)3CCP leading to the 5-tert-butyl-1,3,2,4-dithiazaphospholium cation; a preliminary account of the novel exchange of a cyclic phosphorus by nitrogen in the reaction of with azide N3− leading to 5-tert-butyl-1,3,2,4-dithiadiazolyl

1995 ◽  
Vol 73 (8) ◽  
pp. 1312-1320 ◽  
Author(s):  
Simon Parsons ◽  
Jack Passmore ◽  
Xiaoping Sun ◽  
Manfred Regitz
Keyword(s):  
Sulfur Dioxide ◽  
Low Temperature ◽  
Cycloaddition Reaction ◽  
The Novel ◽  
Multinuclear Nmr ◽  
Tert Butyl ◽  
Nmr Study ◽  
Preliminary Account ◽  
Net Replacement

The cycloaddition reaction of SNS+ (as the AsF6− salt) with 5-tert-butylphosphaacetyline (CH3)3CCP in sulfur dioxide solution at −60 °C gave [Formula: see text], the first identified example of a 1,3,2,4-dithiazaphospholium heterocycle [Formula: see text]. The cycloadduct was characterized by multinuclear NMR (1H, 13C, 14N, 15N, 31P) spectroscopy at low temperature. Reduction of 6π [Formula: see text] in situ with SbPh3 in the presence of Me4NCl led to a radical, which may be the 7π tert-butyl-1,3,2,4-dithiazaphospholyl [Formula: see text]. The reaction of 5-tert-butyl-1,3,2,4-dithiazaphospholium [Formula: see text] with azide N3− surprisingly gave the previously known 5-tert-butyl-1,3,2,4-dithiadiazolyl [Formula: see text]. The conversion of [Formula: see text] to [Formula: see text] by the net replacement of a cyclic phosphorus with nitrogen is unprecedented. Keywords: dithiazaphospholium, dithiazaphospholyl, cycloaddition, multinuclear NMR, ESR.

Copper-Catalyzed Tandem Dehydrocyanation and [3+2] Cyclo­addition Reactions of Phenacylmalononitriles: Regioselective Synthesis of Functionalized 4-Benzoyl-5-cyanopyrazoles under Mild Conditions

Synthesis ◽  
2020 ◽  
Vol 52 (09) ◽  
pp. 1379-1386 ◽  
Author(s):  
Issa Yavari ◽  
Omid Khaledian
Keyword(s):  
Cycloaddition Reaction ◽  
Complexing Agent ◽  
Ambient Conditions ◽  
Weak Base ◽  
Mild Conditions ◽  
Hydrazonoyl Chlorides ◽  
Wide Range ◽  
Nitrile Imines ◽  
In Situ Generation

A novel copper-catalyzed [3+2] cycloaddition reaction with concomitant in situ generation of benzoylacrylonitriles and nitrile imines from phenacylmalononitriles and hydrazonoyl chlorides, respectively, is reported. The reaction was performed using copper(I) chloride as catalyst and N-methylimidazole as a clean complexing agent/weak base to afford the functionalized 4-benzoyl-5-cyanopyrazoles in moderate to good yields and excellent regioselectivity under ambient conditions. This method provides rapid access to a wide range of highly functionalized 4-benzoyl-5-cyanopyrazoles.

Highly diastereo- and enantioselective organocatalytic synthesis of trifluoromethylated erythritols based on the in situ generation of unstable trifluoroacetaldehyde

2021 ◽  
Author(s):  
Kazumasa Funabiki ◽  
Toshiya Gotoh ◽  
Ryunosuke Kani ◽  
Toshiyasu Inuzuka ◽  
Yasuhiro Kubota
Keyword(s):  
Trifluoromethyl Group ◽  
In Situ Generation

A highly diastereo- and enantioselective organocatalytic method to synthesise erythritols bearing a trifluoromethyl group has been investigated.

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