Efficient synthesis of 1,2-benzisothiazoles from o-haloarylamidines and elemental sulfur via N–S/C–S bond formation under transition-metal-free conditions

2018 ◽  
Vol 20 (4) ◽  
pp. 827-831 ◽  
Author(s):  
Hao Xie ◽  
Guozheng Li ◽  
Feng Zhang ◽  
Fuhong Xiao ◽  
Guo-Jun Deng

Facile synthesis of 1,2-benzisothiazoles from amidines and elemental sulfur via N–S/C–S bond formation under transition-metal-free conditions has been developed with good tolerance of a broad range of functional groups.

2021 ◽  
Author(s):  
Xiaoli Huo ◽  
Xiaojuan Chen ◽  
Liya Yu ◽  
Chong Zhang ◽  
Linghui Zeng ◽  
...  

A transition-metal-free, facile and efficient method for the synthesis of 3-alkynylpyrrole-2, 4-dicarboxylates from methylene isocyanides and propiolaldehyde with moderate to good yields has been developed. The direct transformation process and...


2015 ◽  
Vol 2 (3) ◽  
pp. 201-205 ◽  
Author(s):  
Yukiteru Ito ◽  
Mitsuhiro Yoshimatsu

Regioselective H/D exchange reaction of functional groups on heterocycles proceeded via a transition metal-free reductive cyclization of sulfanyl 1,6-diynes using sodium borodeuteride/ethanol-D1.


Synlett ◽  
2018 ◽  
Vol 29 (05) ◽  
pp. 548-555 ◽  
Author(s):  
Liang-Nian He ◽  
Xiao-Fang Liu ◽  
Xiao-Ya Li ◽  
Chang Qiao

Reductive functionalization of CO2 with amines and a reductant, which combines both reduction of CO2 and C–N bond formation in one pot to produce versatile chemicals and energy-storage materials such as formamides, aminals, and methylamines that are usually derived from petroleum feedstock, would be appealing and promising. Herein, we give a brief review on recent developments in the titled CO2 chemistry by employing transition-metal-free catalysis, which can be catalogued as below according to the diversified energy content of the products, that is formamides, aminals, and methylamines being consistent with 2-, 4-, and 6-electron reduction of CO2, respectively. Notably, hierarchical reduction of CO2 with amines to afford at least two products, for example, formamides and methylamines, could be realized with the same catalyst through tuning the hydrosilane type, reaction temperature, or CO2 pressure. Finally, the opportunities and challenges of the reductive functionalization of CO2 with amines are also highlighted.1 Introduction2 2-Electron Reduction of CO2 to Formamide3 6-Electron Reduction of CO2 to Methylamine4 4-Electron Reduction of CO2 to Aminal5 Hierarchical Reduction of CO2 with Amines6 Conclusion


Synlett ◽  
2017 ◽  
Vol 28 (13) ◽  
pp. 1558-1563 ◽  
Author(s):  
Aiwen Lei ◽  
Atul Singh ◽  
Hong Yi ◽  
Guoting Zhang ◽  
Changliang Bian ◽  
...  

We have developed a photoinduced oxidative cross-coupling of thiophenols with alcohols for O–S bond formation. The protocol uses visible light, a metal-free photocatalyst, and oxygen as the oxidant for the selective synthesis of alkyl benzenesulfonates; no ligand co-additive is necessary. Mechanistic studies suggested that the disulfide and alkyl benzenesulfinate are involved as intermediates and that the transformation proceeds by a radical pathway.


Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2395-2409
Author(s):  
Weiwei Qin ◽  
Zhaodong Li ◽  
Yiming Du ◽  
Yue Chen ◽  
Yun-Lin Liu

An efficient, PhI(OAc)2-mediated, radical azidoheteroarylation of alkenes under transition-metal-free conditions is reported by employing TMSN3 and quinoxalin-2(1H)-ones as coupling partners. This domino reaction allows an efficient synthesis of valuable orangoazides containing quinoxalin-2(1H)-one derivatives and could be extended to phosphinyl-alkylated quinoxalin-2(1H)-one in a single step in moderate to excellent yields under mild conditions, as demonstrated by the preliminary antibacterial evaluation against Magnaporthe grisea for the first time. Mechanistic studies revealed that this transformation undergoes a cascade addition pathway controlled by a polar radical.


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