scholarly journals Boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with silylborane and an alkoxy base: expanded scope and mechanistic studies

2015 ◽  
Vol 6 (5) ◽  
pp. 2943-2951 ◽  
Author(s):  
Eiji Yamamoto ◽  
Satoshi Ukigai ◽  
Hajime Ito
Keyword(s):  
Transition Metal ◽  
Mechanistic Studies ◽  
Metal Free

A transition-metal-free method has been developed for the boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides using a silylborane/alkoxy-base reagent. Borylation of (Z)-alkenyl halides proceeded in a stereoretentive manner.

Deuterated Aryl Alkyl Ethers Synthesis via Nucleophilic Etherification of Aryl Alkyl Ethers and Thioethers with Deuterated Alcohols

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1805-1809
Author(s):  
Shuai Li ◽  
Xia Wang ◽  
Xin-Ge Yang ◽  
Gui-Quan Yu ◽  
Xue-Qiang Wang
Keyword(s):  
Transition Metal ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Metal Free ◽  
Wide Range ◽  
Alkyl Ethers

A transition-metal-free etherification protocol that is capable of synthesizing deuterated ethers is described. A wide range of aryl alkyl ethers and thioethers were suitable for this transformation owing to the mild reaction conditions. Besides, a series of sterically bulky deuterated alcohols were successfully incorporated into cyano-substituted arenes. The results of mechanistic studies suggested this reaction might take place via nucleophilic aromatic substitution pathway.

Metal-Free Catalytic Aromatic C–H Borylation

Synlett ◽  
2020 ◽  
Vol 31 (19) ◽  
pp. 1857-1861
Author(s):  
Hua Zhang ◽  
Li Wang
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Rapid Development ◽  
Transition Metal Catalysis ◽  
Mechanistic Studies ◽  
Metal Catalysis ◽  
Promising Alternative ◽  
Metal Free ◽  
History Of ◽  
Near Future

In recent decades, C–H borylation has undergone rapid development and has become one of the most important and efficient methods for the synthesis of organoboron compounds. Although transition-metal catalysis dominates C–H borylation, the metal-free approach has emerged as a promising alternative strategy. This article briefly summarizes the history of metal-free aromatic C–H borylation, including early reports on electrophilic C–H borylation and recent progress in metal-free catalytic intermolecular C–H borylation; it also highlights our recent work on BF3·Et2O-catalyzed C2–H borylation of hetarenes. Despite these recent advances, comprehensive mechanistic studies on various metal-free catalytic aromatic C–H borylations and novel processes with a wider substrate scope are eagerly expected in the near future.

Transition-Metal-Free C–H Arylation of Unactivated Arenes with 8-Hydroxyquinoline as a Promoter

Synthesis ◽  
2018 ◽  
Vol 50 (08) ◽  
pp. 1721-1727 ◽  
Author(s):  
Deyan Wu ◽  
Yinuo Wu ◽  
Xuehua Zheng ◽  
Xu-Nian Wu ◽  
Jing-Yi Chen ◽  
...  
Keyword(s):  
Transition Metal ◽  
Structural Diversity ◽  
Aromatic Substitution ◽  
Mechanistic Studies ◽  
Metal Free ◽  
Aryl Bromides ◽  
Reaction Proceeds ◽  
High Yields ◽  
Biaryl Compounds

A method for the transition-metal-free direct C–H arylation of unactivated arenes is developed with aryl bromides as substrates and 8-hydroxyquinoline as an efficient promoter. A variety of biaryl compounds with structural diversity are obtained in moderate to high yields. Mechanistic studies reveal that the reaction proceeds via a homolytic­ aromatic substitution pathway.

K2S2O8-Mediated Selective Trifluoromethylacylation and Trifluoromethylarylation of Alkenes under Transition-Metal-Free Conditions: Synthetic Scope and Mechanistic Studies

2018 ◽  
Vol 20 (20) ◽  
pp. 6520-6525 ◽  
Author(s):  
Lin Tang ◽  
Zhen Yang ◽  
Xueping Chang ◽  
Jingchao Jiao ◽  
Xiantao Ma ◽  
...  
Keyword(s):  
Transition Metal ◽  
Mechanistic Studies ◽  
Metal Free

Transition-Metal-Free Synthesis of Thiosulfonates through Radical Coupling Reaction

Synlett ◽  
2018 ◽  
Vol 29 (15) ◽  
pp. 2076-2080 ◽  
Author(s):  
Wen-Ting Wei ◽  
Zhiyong Guo ◽  
Guodong Zhou ◽  
Xu-Dong Xu ◽  
Gan-Ping Chen
Keyword(s):  
Transition Metal ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Coupling Process ◽  
Metal Free ◽  
Radical Coupling ◽  
Radical Coupling Reaction ◽  
High Yields

An efficient and practical transition-metal-free radical ­coupling reaction of sulfonyl hydrazides mediated by NIS/K2S2O8 has been developed to afford a variety of biological activity thiosulfonates in moderate to excellent yields. Compared to a known approach for the synthesis of thiosulfonates from sulfonyl hydrazides, this strategy features high yields, mild reaction conditions, and broad substrate scope. The mechanistic studies revealed that the procedure undergoes via a radical cross-coupling process for the construction of S–S bonds.

Dual Roles of Rongalite: Reductive Coupling Reaction to Construct Thiosulfonates Using Sulfonyl Hydrazides

Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 81-85
Author(s):  
Chengrong Ding ◽  
Guofu Zhang ◽  
Qiankun Fan ◽  
Yiyong Zhao ◽  
Huimin Wang
Keyword(s):  
Transition Metal ◽  
Coupling Reaction ◽  
Reductive Coupling ◽  
Mechanistic Studies ◽  
Dual Roles ◽  
Metal Free ◽  
Operational Simplicity

AbstractA tunable and practical transformation of structurally diverse sulfonyl hydrazides into thiosulfonates in the presence of Rongalite (NaHSO2·CH2O) was developed. Transition-metal-free conditions, operational simplicity, and readily available reagents are the striking features of this protocol. It is the first example for the synthesis of thiosulfonates using sulfonyl hydrazides with the assistance of reductant. Additionally, the mechanistic studies revealed that this transformation probably undergoes via a reducing–coupling pathway.

Transition-metal-free catalytic hydroboration reduction of amides to amines

2020 ◽  
Vol 7 (21) ◽  
pp. 3515-3520
Author(s):  
Wubing Yao ◽  
Jiali Wang ◽  
Aiguo Zhong ◽  
Shiliang Wang ◽  
Yinlin Shao
Keyword(s):  
Transition Metal ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Value Added ◽  
Metal Free

The selective catalytic reduction of amides to value-added amine products is a desirable but challenging transformation.

Deaminative carbonylative thioesterification of activated alkylamines with thiophenols under transition-metal-free conditions

2021 ◽  
Author(s):  
Fengqian Zhao ◽  
Xiao-Feng Wu
Keyword(s):  
Free Radical ◽  
Transition Metal ◽  
Metal Free

A transition-metal-free radical carbonylation of activated alkylamines with thiophenols has been successfully developed. Various thioesters were selectively produced with moderate to good yields.

Regioselective C3-H Trifluoromethylation of 2H-Indazole Under Transition-Metal-Free Photoredox Catalysis

2019 ◽  
Author(s):  
Arumugavel Murugan ◽  
Venkata Nagarjuna Babu ◽  
Nagaraj Sabarinathan ◽  
Sharada Duddu. S
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Practical Approach ◽  
Hypervalent Iodine ◽  
Radical Mechanism ◽  
Photoredox Catalysis ◽  
Metal Free

Here we report a visible-light-promoted metal-free regioselective C3-H trifluoromehtylation reaction that proceeds via radical mechanism and which supported by control experiments. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the present trifluoromethylation reaction and synthesis of a library of trifluoromethylated indazoles.

Selective Oxidation of Alcohols Catalyzed by a Transition Metal-Free System of NHPI/DDQ/NaNO2

2011 ◽  
Vol 32 (1) ◽  
pp. 118-122 ◽  
Author(s):  
Lipeng ZHOU ◽  
Chaofeng ZHANG ◽  
Tao FANG ◽  
Bingbing ZHANG ◽  
Ying WANG ◽  
...  
Keyword(s):  
Transition Metal ◽  
Selective Oxidation ◽  
Free System ◽  
Metal Free ◽  
Oxidation Of Alcohols
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