scholarly journals One-Step Synthesis of 2-Alkenecarbodithioate Esters from Substituted Propargyl Ethers, and Their Conversion into Isothiazole Ring through a [4+1] Type Oxidative Ring Closure

2017 ◽  
Vol 12 (6) ◽  
pp. 1934578X1701200
Author(s):  
Kazuaki Shimada ◽  
Fumiya Ishikawa ◽  
Md. Ashraful Alam ◽  
Toshinobu Korenaga
Keyword(s):  
Elemental Sulfur ◽  
Ring Closure ◽  
One Step ◽  
Chloramine T ◽  
In Situ Generation

Treatment of substituted propargyl methyl ethers with a base and elemental sulfur in the presence of a thiolate ion afforded 2-alkenecarbodithioate esters in good yields. The reaction is assumed to proceed through a pathway involving in situ generation of propadienethione intermediates. Further conversion of 2-alkenecarbodithioate esters into 2,3-dihydroisothiazoles were efficiently performed by treating with chloramine-T through a [4+1] type oxidative ring closure via thiocarbonyl S-tosylimides.

scholarly journals A Novel One-step Synthesis of Quinoline-2(1H)-thiones and Selones by Treating 3-Aryl-3-(2-aminophenyl)-1-propyn-3-ols with a Base and Elemental Sulfur or Selenium

2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Kazuaki Shimada ◽  
Hironori Izumi ◽  
Koki Otashiro ◽  
Kensuke Noro ◽  
Shigenobu Aoyagi ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Reactive Species ◽  
Nucleophilic Attack ◽  
Amino Group ◽  
One Step ◽  
High Yields

A one-step conversion of 3-aryl-3-(2-aminophenyl)-1-propyn-3-ols into quinoline-2(1 H)-thiones and quinoline-2(1 H)-selones was achieved only by treating the substrates with n-butyllithium and either elemental sulfur or selenium, respectively. The reactions were assumed to proceed through an intramolecular nucleophilic attack of the neighboring amino group to the plausible in situ generated reactive species related to chalcogenoketenes. The subsequent mCPBA oxidation of quinoline-2(1 H)-selones afforded quinolin-2(1 H)-ones in high yields.

scholarly journals Recent Advances in the Synthesis of Isothiocyanates Using Elemental Sulfur

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1081
Author(s):  
András Gy. Németh ◽  
Péter Ábrányi-Balogh
Keyword(s):  
Natural Products ◽  
Best Practices ◽  
Organic Synthesis ◽  
Elemental Sulfur ◽  
Biologically Active ◽  
Primary Amines ◽  
Pharmaceutical Ingredients ◽  
Recent Developments ◽  
In Situ Generation

Isothiocyanates (ITCs) are biologically active molecules found in several natural products and pharmaceutical ingredients. Moreover, due to their high and versatile reactivity, they are widely used as intermediates in organic synthesis. This review considers the best practices for the synthesis of ITCs using elemental sulfur, highlighting recent developments. First, we summarize the in situ generation of thiocarbonyl surrogates followed by their transformation in the presence of primary amines leading to ITCs. Second, carbenes and amines afford isocyanides, and the further reaction of this species with sulfur readily generates ITCs under thermal, catalytic or basic conditions. Additionally, we also reveal that in the catalyst-free reaction of isocyanides and sulfur, two—until this time overlooked and not investigated—different mechanistic pathways exist.

In situ generation of supported palladium nanoparticles from a Pd/Sn/S chalcogel and applications in 4-nitrophenol reduction and Suzuki coupling

2019 ◽  
Vol 7 (9) ◽  
pp. 4446-4450 ◽  
Author(s):  
Xinyao Shan ◽  
Ning Sui ◽  
Wengang Liu ◽  
Manhong Liu ◽  
Jian Liu
Keyword(s):  
Palladium Nanoparticles ◽  
Suzuki Coupling ◽  
Pd Nanoparticles ◽  
Nitrophenol Reduction ◽  
One Step ◽  
Supported Palladium ◽  
In Situ Generation ◽  
Catalytic Applications

A one-step in situ route to obtain well-defined and size-controllable Pd nanoparticles was reported and employed for catalytic applications.

scholarly journals Towards coupling direct activation of methane with in situ generation of H2O2

2019 ◽  
Vol 9 (18) ◽  
pp. 5142-5149
Author(s):  
Amin Delparish ◽  
Shamayita Kanungo ◽  
John van der Schaaf ◽  
M. Fernanda Neira d'Angelo
Keyword(s):  
Direct Activation ◽  
Oxidation Of Methane ◽  
One Step ◽  
In Situ Generation ◽  
The One ◽  
Shed Light

This study aims to shed light on the one-step oxidation of methane to methanol with in situ generated H2O2 by means of a wall-coated catalytic microreactor.

scholarly journals Synthesis and selected transformations of 2-unsubstituted 1-(adamantyloxy)imidazole 3-oxides: straightforward access to non-symmetric 1,3-dialkoxyimidazolium salts

2019 ◽  
Vol 15 ◽  
pp. 497-505 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Małgorzata Celeda ◽  
Katarzyna Urbaniak ◽  
Marcin Jasiński ◽  
Vladyslav Bakhonsky ◽  
...  
Keyword(s):  
Hydrobromic Acid ◽  
Room Temperature ◽  
Elemental Sulfur ◽  
Acid Anhydride ◽  
Monomeric Form ◽  
New Class ◽  
Raney Ni ◽  
In Situ Generation ◽  
Alkylation Reactions

Adamantyloxyamine reacts with formaldehyde to give N-(adamantyloxy)formaldimine as a room-temperature-stable compound that exists in solution in monomeric form. This product was used for reactions with α-hydroxyiminoketones leading to a new class of 2-unsubstituted imidazole 3-oxides bearing the adamantyloxy substituent at N(1). Their reactions with 2,2,4,4-tetramethylcyclobutane-1,3-dithione or with acetic acid anhydride occurred analogously to those of 1-alkylimidazole 3-oxides to give imidazol-2-thiones and imidazol-2-ones, respectively. Treatment of 1-(adamantyloxy)imidazole 3-oxides with Raney-Ni afforded the corresponding imidazole derivatives without cleavage of the N(1)–O bond. Finally, the O-alkylation reactions of the new imidazole N-oxides with 1-bromopentane or 1-bromododecane open access to diversely substituted, non-symmetric 1,3-dialkoxyimidazolium salts. Adamantyloxyamine reacts with glyoxal and formaldehyde in the presence of hydrobromic acid yielding symmetric 1,3-di(adamantyloxy)-1H-imidazolium bromide in good yield. Deprotonation of the latter with triethylamine in the presence of elemental sulfur allows the in situ generation of the corresponding imidazol-2-ylidene, which traps elemental sulfur yielding a 1,3-dihydro-2H-imidazole-2-thione as the final product.

In situ generation and trapping of thioimidates: an intermolecular tandem reaction to 4-acylimino-4H-3,1-benzothiazines

RSC Advances ◽  
2016 ◽  
Vol 6 (19) ◽  
pp. 15430-15440 ◽  
Author(s):  
Christian Steinebach ◽  
Anna-Christina Schulz-Fincke ◽  
Gregor Schnakenburg ◽  
Michael Gütschow
Keyword(s):  
Tandem Reaction ◽  
One Step ◽  
In Situ Generation ◽  
Acyl Donors

The proton-catalyzed transformation of 2-thioureidobenzonitriles in the presence of acyl donors provides a convenient one-step entry to 4-acylimino-4H-3,1-benzothiazines.

scholarly journals 2-Unsubstituted Imidazole N-Oxides as Novel Precursors of Chiral 3-Alkoxyimidazol-2-ylidenes Derived from trans-1,2-Diaminocyclohexane and Other Chiral Amino Compounds

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4398 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Małgorzata Celeda ◽  
Marcin Jasiński ◽  
Katarzyna Urbaniak ◽  
Przemysław J. Boratyński ◽  
...  
Keyword(s):  
Amino Acids ◽  
Elemental Sulfur ◽  
Amino Alcohols ◽  
Primary Amines ◽  
Analogous Reaction ◽  
Imidazolium Salts ◽  
Amino Compounds ◽  
In Situ Generation

‘Desymmetrization’ of trans-1,2-diaminocyclohexane by treatment with α,ω-dihalogenated alkylation reagents leads to mono-NH2 derivatives (‘primary-tertiary diamines’). Upon reaction with formaldehyde, these products formed monomeric formaldimines. Subsequently, reactions of the formaldimines with α-hydroxyiminoketones led to the corresponding 2-unsubstituted imidazole N-oxide derivatives, which were used here as new substrates for the in situ generation of chiral imidazol-2-ylidenes. Upon O-selective benzylation, new chiral imidazolium salts were obtained, which were deprotonated by treatment with triethylamine in the presence of elemental sulfur. Under these conditions, the intermediate imidazol-2-ylidenes were trapped by elemental sulfur, yielding the corresponding chiral non-enolizable imidazole-2-thiones in good yields. Analogous reaction sequences, starting with imidazole N-oxides derived from enantiopure primary amines, amino alcohols, and amino acids, leading to the corresponding 3-alkoxyimidazole-2-thiones were also studied.

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