97025-65-5Relevant academic research and scientific papers
Silver-Catalyzed Cross-Olefination of Donor and Acceptor Diazo Compounds: Use of N-Nosylhydrazones as Diazo Surrogate
Liu, Zhaohong,Liu, Binbin,Zhao, Xue-Feng,Wu, Yan-Bo,Bi, Xihe
, p. 928 - 932 (2017)
The cross-olefination reaction of donor and acceptor diazo compounds was explored. The use of N-nosylhydrazones as diazo surrogates and the dependence on silver catalysis were crucial for the reaction development. A variety of (hetero)aryl N-nosylhydrazones and α-diazo esters, amides, and phosphonates were compatible, and the functionalized alkene products were afforded in good to high yields with moderate (Z)/(E) selectivities. The experimental and DFT calculation results suggest that the cross-selectivity is due to selective activation of the silver catalyst for donor diazo compounds.
Coupling of N -Nosylhydrazones with Nitrosoarenes: Transition-Metal-Free Approach to (Z)- N -Arylnitrones
Liu, Tingting,Liu, Zhaohong,Liu, Zhenhua,Hu, Donghua,Wang, Yeming
supporting information, p. 1728 - 1736 (2018/02/14)
An efficient and transition-metal-free protocol for the synthesis of (Z)- N -arylnitrones from the direct coupling of N -nosylhydrazones with nitrosoarenes under mild conditions is described. The protocol is compatible with a wide range of functional groups placed on both the reagents and provided the corresponding nitrones in good to excellent yields by simple recrystallization process. The use of these 1,3-dipoles for the synthesis of substituted indoles is elaborated for 2,3-diphenyl-1 H -indole.
Preparation method of mild diazomethane derivative
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Paragraph 0113; 0114; 0119, (2017/08/28)
The invention discloses a preparation method of a mild diazomethane derivative. The preparation method comprises that EWG-substituted benzene sulfonyl chloride and hydrazine hydrate undergo a reaction to produce EWG-substituted benzene sulfonyl chloride, the EWG-substituted benzene sulfonyl chloride and aldehyde or ketone undergo a reaction to produce EWG-substituted benzenesulfonylhydrazone, and the EWG-substituted benzenesulfonylhydrazone, a base and an organic solvent are mixed and undergo a replacement reaction to produce a diazomethane derivative. The diazomethane derivative is not separated and purified and is further used for a tension small ring synthesis reaction and an insertion reaction. The benzene ring of benzenesulfonylhydrazone is introduced with an electron-withdrawing group EWG, and through electron effects and steric hindrance effects, the benzenesulfonyl group on the benzenesulfonylhydrazone is easily separated so that a diazomethane derivative is produced under very mild conditions and especially at the room temperature.
Silver(i)-promoted insertion into X-H (X = Si, Sn, and Ge) bonds with N-nosylhydrazones
Liu, Zhaohong,Li, Qiangqiang,Yang, Yang,Bi, Xihe
supporting information, p. 2503 - 2506 (2017/03/08)
Silver(i)-promoted carbene insertion into X-H (X = Si, Sn, and Ge) bonds has been realized by using unstable diazo compounds, which are generated in situ from N-nosylhydrazones as carbene precursors. The reaction tolerates a wide range of functional groups and delivers a number of valuable silicon-containing compounds in very high yields (up to 96%). Moreover, organostannanes and organogermanes were as well effectively obtained in very good yields under optimal conditions.
Silver-Catalyzed [2+1] Cyclopropenation of Alkynes with Unstable Diazoalkanes: N-Nosylhydrazones as Room-Temperature Decomposable Diazo Surrogates
Liu, Zhaohong,Li, Qiangqiang,Liao, Peiqiu,Bi, Xihe
supporting information, p. 4756 - 4760 (2017/04/14)
The [2+1] cycloaddition of alkynes with diazo compounds represents one of the most powerful and reliable methods for the construction of cyclopropenes. However, it remains a formidable challenge to accomplish the cyclopropenation of alkynes with non-stabilized diazoalkanes, owing to the fact that such compounds are unstable and prone to detonation. Herein, we report a general silver-catalyzed cyclopropenation reaction of alkynes with unstable diazoalkanes, by for the first time the discovery and application of N-nosylhydrazones as room-temperature decomposiable diazo surrogates. This method allows for the efficient assembly a wide variety of cyclopropene derivatives that are otherwise difficult to access by conventional methods.
