Sulfur-Mediated Decarboxylative Coupling of 2-Nitrobenzyl Alcohols and Arylacetic Acids

Synlett ◽  
2020 ◽  
Vol 31 (11) ◽  
pp. 1112-1116
Author(s):  
Tung T. Nguyen ◽  
Nam T. S. Phan ◽  
Khang X. Nguyen ◽  
Duyen K. Nguyen ◽  
Phuc H. Pham ◽  
...  
Keyword(s):  
Transition Metals ◽  
Nitrogen Source ◽  
Elemental Sulfur ◽  
New Method ◽  
Complex Structures ◽  
Reaction Conditions ◽  
Mild Conditions ◽  
Decarboxylative Coupling ◽  
Arylacetic Acids

We report a new method for the synthesis of substituted quinazolines by the condensation of 2-nitrobenzyl alcohols with arylacetic acids. The transformation requires the use of urea as a nitrogen source, elemental sulfur as a promoter, DABCO as a base, and DMSO as a solvent. Functionalities such as chloro, fluoro, trifluoromethyl, thienyl, and indolyl groups were all compatible with the reaction conditions. Because our method uses stable simple substrates to obtain the N,N-heterocycles in the absence of transition metals, it offers a potential pathway for preparing complex structures under mild conditions.

scholarly journals Functionalization of C–H bonds in acetophenone oximes with arylacetic acids and elemental sulfur

RSC Advances ◽  
2020 ◽  
Vol 10 (19) ◽  
pp. 11024-11032 ◽  
Author(s):  
Phuc H. Pham ◽  
Khang X. Nguyen ◽  
Hoai T. B. Pham ◽  
Thien T. Tran ◽  
Tung T. Nguyen ◽  
...  
Keyword(s):  
Transition Metals ◽  
Elemental Sulfur ◽  
Arylacetic Acids ◽  
Acetophenone Oxime

Annulation of acetophenone oxime acetates, arylacetic acids or esters, and elemental sulfur in absence of transition metals is reported.

Iron-Promoted Decarboxylation of Arylacetic Acids for the Synthesis of Aromatic Nitriles with Sodium Nitrite as the Nitrogen Source

Synlett ◽  
2020 ◽  
Vol 31 (18) ◽  
pp. 1805-1808 ◽  
Author(s):  
Zhenpeng Shen ◽  
Wenbo Liu ◽  
Xinzhe Tian ◽  
Yun-Lai Ren ◽  
Zhe Zhao
Keyword(s):  
Nitrogen Source ◽  
Functional Groups ◽  
Sodium Nitrite ◽  
Aromatic Nitriles ◽  
Mild Conditions ◽  
Arylacetic Acids

AbstractA new and effective method was developed for the synthesis of aromatic nitriles from arylacetic acids by using NaNO2 as the nitrogen source and Fe(OTf)3 as the promoter at 50 °C. A series of arylacetic acids underwent this transformation to give the targeted products in yields of 51–90%. Because of the mild conditions, the reaction is compatible with a broad range of functional groups, including ester, carboxy, hydroxy, acetamido, halo, nitro, cyano, methoxy, and even highly reactive formyl groups.

Synthesis of 2-Arylbenzothiazol-5-amines from N,N-Dialkyl-3-nitroanilines

Synlett ◽  
2020 ◽  
Vol 31 (18) ◽  
pp. 1813-1816 ◽  
Author(s):  
Tung T. Nguyen ◽  
Nam T. S. Phan ◽  
Hang T. Pham ◽  
Tuan H. Ho ◽  
Duy Q. Do ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Reaction Conditions ◽  
Simple Method ◽  
Simple Route ◽  
Arylacetic Acids ◽  
Derivatives Of

AbstractWe report a simple method for coupling of N,N-dialkyl-3-nitroarenes, elemental sulfur, and activated sp3 C–H bonds in 2-methylazaarenes or arylacetic acids to afford derivatives of 2-arylbenzothiazol-5-amines. Only DABCO base was required, and many heterocycles such as imidazoles, oxazoles, quinolines, and thiophenes were compatible with the reaction conditions. Our approach offers a simple route to useful substituted thiazol-5-amines from commercially available nitroarenes.

Synthesis of Cyanamides from Cyanogen Bromide under Mild Conditions through N-Cyanation of Allylic Tertiary Amines

Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2675-2679 ◽  
Author(s):  
Chenghui Sun ◽  
Honggang Liang ◽  
Lingxiang Bao ◽  
Yao Du ◽  
Yiying Zhang ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reaction ◽  
Cyanogen Bromide ◽  
New Method ◽  
Nucleophilic Substitution Reaction ◽  
Tertiary Amines ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions ◽  
One Step

Cyanamides were selectively formed through a one-step nucleophilic substitution reaction of allylic tertiary amines with cyanogen bromide. Because of the mild reaction conditions and good yields of the reaction, as well as the commercial availability of the starting materials, this new method represents a valuable tool for the synthesis of cyan­amides through an N-deallylation reaction and an N-cyanation reaction in one pot.

Elemental sulfur mediated synthesis of pyrrolo[1,2-α]quinoxalines from 1-(2-nitroaryl) pyrroles

Synthesis ◽  
2021 ◽  
Author(s):  
Tung Nguyen ◽  
Tuan Ho ◽  
Nam T. S. Phan ◽  
Nhu Phan ◽  
Thuyen Ho ◽  
...  
Keyword(s):  
Transition Metals ◽  
Elemental Sulfur ◽  
Coupling Reagents ◽  
Benzyl Alcohols ◽  
Fused Heterocycles ◽  
Arylacetic Acids ◽  
Harsh Conditions

Methods to afford pyrrolo[1,2-α]quinoxalines often require the use of prefunctionalized aniline precursors, transition metals, and/or harsh conditions. Herein we describe a simple coupling of 1-(2-nitroaryl)pyrroles and arylacetic acids, in the presence of elemental sulfur, to furnish the fused heterocycles in good yields. The conditions were compatible with many functionalities including ester, nitrile, halogen, and nitro groups. Use of benzyl alcohols and picoline coupling reagents was also attempted.

Ketones from Nickel-Catalyzed Decarboxylative, Non-Symmetric Cross-Electrophile Coupling of Carboxylic Acid Esters

2019 ◽  
Author(s):  
Jiang Wang ◽  
Brian P. Cary ◽  
Peyton Beyer ◽  
Samuel H. Gellman ◽  
Daniel Weix
Keyword(s):  
Carboxylic Acid ◽  
Solid Support ◽  
Reaction Conditions ◽  
Decarboxylative Coupling ◽  
New Strategy ◽  
The Cross ◽  
Acyl Donors ◽  
Acid Esters

A new strategy for the synthesis of ketones is presented based upon the decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with S-2-pyridyl thioesters. The reactions are selective for the cross-coupled product because NHP esters act as radical donors and the thioesters act as acyl donors. The reaction conditions are general and mild, with over 40 examples presented, including larger fragments and the 20-mer peptide Exendin(9-39) on solid support.

Imidazole-based Cu(i)-catalyzed click polymerization of diazides and diynes under mild conditions

2021 ◽  
Author(s):  
Baixue Li ◽  
Jia Wang ◽  
Anjun Qin ◽  
Ben Zhong Tang
Keyword(s):  
Reaction Conditions ◽  
Mild Conditions ◽  
Click Polymerization

An efficient imidazole-based Cu(i)-catalyzed azide–alkyne click polymerization under mild reaction conditions was developed.

scholarly journals The Fluoride Anion-Catalyzed Sulfurization of Thioketones with Elemental Sulfur Leading to Sulfur-Rich Heterocycles: First Sulfurization of Thiochalcones

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 822
Author(s):  
Grzegorz Mlostoń ◽  
Jakub Wręczycki ◽  
Katarzyna Urbaniak ◽  
Dariusz M. Bieliński ◽  
Heinz Heimgartner
Keyword(s):  
Elemental Sulfur ◽  
Fluoride Anion ◽  
Ring Size ◽  
Mild Conditions ◽  
Tetrabutylammonium Fluoride ◽  
Cesium Fluoride ◽  
Secondary Reactions ◽  
Derivatives Of

Fluoride anion was demonstrated as a superior activator of elemental sulfur (S8) to perform sulfurization of thioketones leading to diverse sulfur-rich heterocycles. Due to solubility problems, reactions must be carried out either in THF using tetrabutylammonium fluoride (TBAF) or in DMF using cesium fluoride (CsF), respectively. The reactive sulfurizing reagents are in situ generated, nucleophilic fluoropolysulfide anions FS(8−x)−, which react with the C=S bond according to the carbophilic addition mode. Dithiiranes formed thereby, existing in an equilibrium with the ring-opened form (diradicals/zwitterions) are key-intermediates, which undergo either a step-wise dimerization to afford 1,2,4,5-tetrathianes or an intramolecular insertion, leading in the case of thioxo derivatives of 2,2,4,4-tetramethylcyclobutane-1,3-dione to ring enlarged products. In reactions catalyzed by TBAF, water bounded to fluoride anion via H-bridges and forming thereby its stable hydrates is involved in secondary reactions leading, e.g., in the case of 2,2,4,4-tetramethyl-3-thioxocyclobutanone to the formation of some unexpected products such as the ring enlarged dithiolactone and ring-opened dithiocarboxylate. In contrast to thioketones, the fluoride anion catalyzed sulfurization of their α,β-unsaturated analogues, i.e., thiochalcones is slow and inefficient. However, an alternative protocol with triphenylphosphine (PPh3) applied as a catalyst, offers an attractive approach to the synthesis of 3H-1,2-dithioles via 1,5-dipolar electrocyclization of the in situ-generated α,β-unsaturated thiocabonyl S-sulfides. All reactions occur under mild conditions and can be considered as attractive methods for the preparation of sulfur rich heterocycles with diverse ring-size.

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