A Simple and Efficient Method for the Synthesis of α,β-Unsaturated Acyl Azo Compounds with NaNO2-Acetic Anhydride Under Mild Conditions

2002 ◽  
Vol 49 (2) ◽  
pp. 213-215 ◽  
Author(s):  
Xiao-Chuan Li ◽  
Yu-Lu Wang ◽  
Jin-Ye Wang
Keyword(s):  
Acetic Anhydride ◽  
Efficient Method ◽  
Azo Compounds ◽  
Mild Conditions ◽  
Unsaturated Acyl

An Efficient Method for the Oxidation of Aryl Substituted semicarbazides to aryl azo compounds with NaNO2-Ac2O

2002 ◽  
Vol 2002 (6) ◽  
pp. 284-285 ◽  
Author(s):  
Xiao-Chuan Li ◽  
Yu-Lu Wang ◽  
Jin-Ye Wang
Keyword(s):  
Acetic Anhydride ◽  
Efficient Method ◽  
Azo Compounds ◽  
Oxidizing Agent ◽  
Mild Conditions ◽  
First Time

In this paper 18 aryl substituted semicarbazides undergo rapid oxidation to the corresponding aryl azo compounds using NaNO2-acetic anhydride as a novel oxidizing agent under mild conditions for the first time.

A Simple and Efficient Method for the Dehydrogenation of Symmetric Hydrazo Compounds with NaNO2/NaHSO4•H2O/SiO2

2002 ◽  
Vol 2002 (11) ◽  
pp. 540-541 ◽  
Author(s):  
Xiao-Chuan Li ◽  
Yu-Lu Wang ◽  
Jin-Ye Wang
Keyword(s):  
Efficient Method ◽  
Azo Compounds ◽  
Mild Conditions ◽  
First Time

In this paper, 18 symmetric hydrazo compounds undergo rapid oxidation to corresponding azo compounds using NaNO2/NaHSO4•H2O/SiO2 as a novel oxidising agent under mild conditions for the first time.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

Organophosphane-Catalyzed Construction of Functionalized 2-Ylideneoxindoles via Direct β-Acylation

Synthesis ◽  
2021 ◽  
Author(s):  
Wey-Chyng Jeng ◽  
Po-Chung Chien ◽  
Sandip Sambhaji Vagh ◽  
Athukuri Edukondalu ◽  
Wenwei Lin
Keyword(s):  
Intramolecular Cyclization ◽  
Efficient Method ◽  
Bond Cleavage ◽  
Scale Up ◽  
Acyl Chlorides ◽  
Metal Free ◽  
Mild Conditions ◽  
Synthetic Utility ◽  
Mechanistic Investigations ◽  
Synthetic Transformations

We report an efficient method for the direct β-acylation of 2-ylideneoxindoles with acyl chlorides in the presence of base-catalyzed by organophosphanes. A variety of functionalized 2-ylideneoxindoles were prepared in moderate to good yields under metal-free and mild conditions via a tandem phospha-Michael/O-acylation/intramolecular cyclization/ rearrangement sequence. The mechanistic investigations revealed that the C-O bond cleavage on possible betaine intermediate is the key step for the installation of keto-functionality at β-position of 2-ylideneoxindoles in a highly stereospecific manner. The synthetic utility of this protocol could also be proven by scale-up reactions and synthetic transformations of the products.

Efficient Synthesis of 3,4-Disubstituted 7-Azaindoles Employing SEM as a Dual Protecting–Activating Group

Synlett ◽  
2019 ◽  
Vol 30 (20) ◽  
pp. 2273-2278 ◽  
Author(s):  
Piroska Gyárfás ◽  
János Gerencsér ◽  
Warren S. Wade ◽  
László Ürögdi ◽  
Zoltán Novák ◽  
...  
Keyword(s):  
Functional Groups ◽  
Efficient Method ◽  
Reaction Times ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Efficient Synthesis ◽  
Mild Conditions

An efficient method for nucleophilic aromatic substitution on 7-azaindoles has been developed. The reaction is facilitated by the unique dual influence of SEM as both protecting and activating group, permitting mild conditions and short reaction times that are compatible with sensitive functional groups. The method is suitable for the synthesis of a broad range of products, most notably ethers.

A multicomponent reaction on a ‘free’ KCC-1 catalyst at room temperature under solvent free conditions by visible light

RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54236-54240 ◽  
Author(s):  
Seyed Mohsen Sadeghzadeh
Keyword(s):  
Visible Light ◽  
Multicomponent Reaction ◽  
Efficient Method ◽  
Room Temperature ◽  
Solvent Free ◽  
Green Protocol ◽  
Mild Conditions ◽  
Solvent Free Conditions

A green and efficient method for the synthesis of various triazolo[1,2-a]indazoletrione under mild conditions is reported, that making it a genuinely green protocol.

A Highly Efficient Method for the Bromination of Alkenes, Alkynes and Ketones Using Dimethyl Sulfoxide and Oxalyl Bromide

Synthesis ◽  
2018 ◽  
Vol 50 (21) ◽  
pp. 4325-4335 ◽  
Author(s):  
Hongyu Tian ◽  
Baoguo Sun ◽  
Rui Ding ◽  
Jiaqi Li ◽  
Wenyi Jiao ◽  
...  
Keyword(s):  
Dimethyl Sulfoxide ◽  
Efficient Method ◽  
Low Cost ◽  
Reaction Times ◽  
Attractive Alternative ◽  
Mild Conditions ◽  
Highly Efficient

The pairing of DMSO and oxalyl bromide is reported as a highly efficient brominating reagent for various alkenes, alkynes and ketones. This bromination approach demonstrates remarkable advantages, such as mild conditions, low cost, short reaction times, provides excellent yields in most cases and represents a very attractive alternative for the preparation of dibromides and α-bromoketones.

Formation of 1,3,4-Oxadiazoles by Cyclisation of Acetoacetanilide Acylhydrazones under Mild Conditions

2002 ◽  
Vol 2002 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Igor B. Dzvinchuk ◽  
Sergey A. Kartashov ◽  
Myron O. Lozinskii ◽  
Eduard B. Rusanov ◽  
Alexander N. Chernega
Keyword(s):  
Acetic Anhydride ◽  
Acid Catalysis ◽  
Mild Conditions

Selective and efficient cyclisation of acetoacetanilide acylhydrazones into previously inaccessible 3-acetyl-2-anilinocarbonylmethyl-2,3-dihydro-2-methyl-1,3,4-oxadiazoles was achieved in acetic anhydride by use of acid catalysis at 40–50°C.

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