Synthesis of α-Keto Thioamides by Metal-Free C═C Bond Cleavage in Enaminones Using Elemental Sulfur

2018 ◽  
Vol 84 (2) ◽  
pp. 1064-1069 ◽  
Author(s):  
Lu Gan ◽  
Yong Gao ◽  
Li Wei ◽  
Jie-Ping Wan
Keyword(s):  
Elemental Sulfur ◽  
Bond Cleavage ◽  
Metal Free

scholarly journals Metal-free direct thiocarbamation of imidazopyridines with carbamoyl chloride and elemental sulfur

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 54013-54016 ◽  
Author(s):  
Jian-Chao Deng ◽  
Shi-Bin Zhuang ◽  
Quan-Zhu Liu ◽  
Zi-Wei Lin ◽  
Yu-Liang Su ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Metal Free

Metal-free direct thiocarbamation of imidazopyridines using elemental sulfur.

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.

Metal-Free Dehydrogenative Double C–H Sulfuration To Access Thieno[2,3-b]indoles Using Elemental Sulfur

2019 ◽  
Vol 84 (20) ◽  
pp. 12946-12959 ◽  
Author(s):  
Jianming Liu ◽  
Yanyan Zhang ◽  
Yuanyuan Yue ◽  
Zhixian Wang ◽  
Huibin Shao ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Metal Free

I2/TBHP-Promoted Approach to α-Keto Esters from Trifluoromethyl β-Diketones and Alcohols via C–C Bond Cleavage

Synlett ◽  
2017 ◽  
Vol 28 (15) ◽  
pp. 2018-2023 ◽  
Author(s):  
Xiang Fang ◽  
Xueyan Yang ◽  
Tongle Shao ◽  
Jun Zhou ◽  
Chen Jin ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Coupling Reaction ◽  
Mechanistic Studies ◽  
Metal Free ◽  
Oxidation Pathway ◽  
Keto Esters ◽  
Oxidative Coupling Reaction

A metal-free oxidative coupling reaction of trifluoromethyl β-diketones with alcohols for the synthesis of α-keto esters in good to excellent yields has been developed. Preliminary mechanistic studies suggest that an I2/TBHP promoted sequential iodination, C–C bond cleavage, C–O bond formation and oxidation pathway is involved in this reaction.

scholarly journals Selective C-N σ Bond Cleavage in Azetidinyl Amides under Transition Metal-Free Conditions

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 459 ◽  
Author(s):  
Hengzhao Li ◽  
Zemin Lai ◽  
Adila Adijiang ◽  
Hongye Zhao ◽  
Jie An
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Transfer Reaction ◽  
Bond Cleavage ◽  
Electron Transfer Reaction ◽  
Amide Bond ◽  
Single Electron Transfer ◽  
Reaction Conditions ◽  
Metal Free ◽  
Single Electron Transfer Reaction

Functionalization of amide bond via the cleavage of a non-carbonyl, C-N σ bond remains under-investigated. In this work, a transition-metal-free single-electron transfer reaction has been developed for the C-N σ bond cleavage of N-acylazetidines using the electride derived from sodium dispersions and 15-crown-5. Of note, less strained cyclic amides and acyclic amides are stable under the reaction conditions, which features the excellent chemoselectivity of the reaction. This method is amenable to a range of unhindered and sterically encumbered azetidinyl amides.

scholarly journals Na2CO3-promoted thioesterification via N–C bond cleavage of amides to construct thioester derivatives

2019 ◽  
Vol 43 (11-12) ◽  
pp. 486-492
Author(s):  
Jiasi Tao ◽  
Weijie Yu ◽  
Jin Luo ◽  
Tao Wang ◽  
Wanling Ge ◽  
...  
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Metal Free

A mild, efficient, and transition-metal-free catalytic strategy is developed to construct thioesters via selective N–C bond cleavage of Boc2-activated primary amides. This strategy is successfully carried out with stoichiometric Na2CO3 as the base and provides the corresponding products in moderate to excellent yields.

Metal-Free Aminothiation of Alkynes: Three-Component Tandem Annulation toward Indolizine Thiones from 2-Alkylpyridines, Ynals, and Elemental Sulfur

2019 ◽  
Vol 84 (19) ◽  
pp. 12639-12647 ◽  
Author(s):  
Zhengwang Chen ◽  
Pei Liang ◽  
Fan Xu ◽  
Zhen Deng ◽  
Lipeng Long ◽  
...  
Keyword(s):  
Elemental Sulfur ◽  
Metal Free

Catalytic conversion of ketones to esters via C(O)–C bond cleavage under transition-metal free conditions

2020 ◽  
Vol 56 (58) ◽  
pp. 8143-8146
Author(s):  
Murugan Subaramanian ◽  
Palmurukan M. Ramar ◽  
Jagannath Rana ◽  
Virendra Kumar Gupta ◽  
Ekambaram Balaraman
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Catalytic Conversion ◽  
Metal Free

The catalytic conversion of ketones to esters via C(O)–C bond cleavage under transition-metal free conditions is reported.

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