Rh(iii)-Catalyzedortho-C–H alkynylation ofN-phenoxyacetamides with hypervalent iodine-alkyne reagents at room temperature

2018 ◽  
Vol 16 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Sisheng Hu ◽  
Liang Lu ◽  
Tongyang Zhu ◽  
Qian Wu ◽  
Ying Chen ◽  
...  

Directing group ONHR preservedortho-alkynylation under mild conditions catalyzed by rhodium is reported.

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.


Synthesis ◽  
2017 ◽  
Vol 49 (18) ◽  
pp. 4303-4308 ◽  
Author(s):  
Dong Li ◽  
Chuancheng Zhang ◽  
Qiang Yue ◽  
Zhen Xiao ◽  
Xianglan Wang ◽  
...  

An efficient protocol for the synthesis of O-aroyl-N,N-dimethylhydroxylamines, which are important electrophilic amination reagents, is described. The reaction between carboxylic acids and N,N-dimethylformamide is mediated by hypervalent iodine and occurs under mild conditions at room temperature to give the desired products in good yields. The process shows good functional group compatibility and air and moisture tolerance.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi-Zhou Zhan ◽  
Nan Xiao ◽  
Wei Shu

AbstractThe development of straightforward synthesis of regio- and stereodefined alkenes with multiple aliphatic substituents under mild conditions is an unmet challenge owing to competitive β-hydride elimination and selectivity issues. Herein, we report the nickel-catalyzed intermolecular cross-dialkylation of alkynes devoid of directing or activating groups to afford multiple aliphatic substituted alkenes in a syn-selective fashion at room temperature. The combination of two-electron oxidative cyclometallation and single-electron cross-electrophile coupling of nickel enables the syn-cross-dialkylation of alkynes at room temperature. This reductive protocol enables the sequential installation of two different alkyl substituents onto alkynes in a regio- and stereo-selective manner, circumventing the tedious preformation of sensitive organometallic reagents. The synthetic utility of this protocol is demonstrated by efficient synthesis of multi-substituted unfunctionalized alkenes and diverse transformations of the product.


2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>


2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>


Synthesis ◽  
2020 ◽  
Author(s):  
Narendra R. Chaubey ◽  
Anant R. Kapdi ◽  
Biswanath Maity

AbstractOrganophotocatalytic C–H bond functionalization has attracted a lot of attention in the past several years due to the possibility of catalyzing reactions in a metal- and peroxide-free environment. Continuing on these lines, an organophotoredox-catalyzed C–H functionalization of imidazo[1,2-a]pyridines and related heterocycles with bromomalonates under mild conditions is reported, providing excellent yields of the products at room temperature. This is the first report involving malonates as coupling partners leading to the synthesis of a range of functionalized products including total synthesis of zolpidem, a sedative­-hypnotic drug molecule.


RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 5080-5085
Author(s):  
Lei Zheng ◽  
Chen Sun ◽  
Wenhao Xu ◽  
Alexandr V. Dushkin ◽  
Nikolay Polyakov ◽  
...  

We have developed I2/KH2PO2 and KI/P(OEt)3 strategy syntheses of esters from carboxylic acids and alcohols through different reaction mechanisms. The advantages of present protocol: mild conditions and late-stage diversification of natural products.


2001 ◽  
Vol 56 (12) ◽  
pp. 1360-1368 ◽  
Author(s):  
Robert Weiss ◽  
Frank Pühlhofer

Abstract 4-Fluorobenzenesulfonyl chloride (1) and pentafluorobenzenesulfonyl chloride (2) are transformed into the corresponding N-sulfonylpyridinium triflates 4a-d by treatment with one equivalent of the reagent pair L/TMSOTf (L = 4-dimethylaminopyridine (DMAP), 4-ferf-butylpyridine (TBUPY), 1-methylimidazole (NMI); TMSOTf = trimethylsilyl triflate). Due to the electrostatic effect of the sulfonylonio function, SNAr reactions on these systems can be performed under mild conditions. So the reaction of 2 with excess DMAP/TMSOTf leads by way of peronio substitution to hexakis[(4-dimethylamino)-l-pyridinio]benzene hexa-kis(trifluoromethansulfonate) (7) [22] at room temperature. Additionally, a new reaction path to 4-(1-pyridinio)-substituted benzenesulfonamides, a class of pharmaceutically interesting substances, is shown.


RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 100401-100407 ◽  
Author(s):  
Rajamani Rajmohan ◽  
Subramaniyan Gayathri ◽  
Pothiappan Vairaprakash

In a simple and conceptually designed method for the dehydration of fructose on a solid support, 5-hydroxymethylfurfural (HMF) was synthesized in more than 95% isolated yield from fructose under very mild conditions at room temperature.


2020 ◽  
Author(s):  
Albert Granados ◽  
Anna Balleteros ◽  
Adelina Vallribera

An electrophilic enantioselective catalytic method for the a-pentafluoroethylation of alkyl 1-indanone-2-carboxylates is described. Under the use of La(OTf)<sub>3</sub> in combination with (<i>S,R</i>)-indanyl-<i>pybox</i> ligand good results in terms of yield and enantioselectivities were achieved (up to 89% <i>ee</i>). The reaction proceeds under mild conditions leading to the formation of enantioenriched quaternary centers. This methodology uses an hypervalent iodine(III)-CF<sub>2</sub>CF<sub>3</sub> reagent and mechanistic investigations are consistent with the involvement of a radical pathway.


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