74346-22-8Relevant academic research and scientific papers
Electrochemical Semipinacol Rearrangements of Allylic Alcohols: Construction of All-Carbon Quaternary Stereocenters
Kang, Jun-Chen,Tu, Yong-Qiang,Dong, Jia-Wei,Chen, Chao,Zhou, Jia,Ding, Tong-Mei,Zai, Jian-Tao,Chen, Zhi-Min,Zhang, Shu-Yu
, p. 2536 - 2540 (2019)
The first examples of electrochemical trifluoromethylation and sulfonylation/semipinacol rearrangements of allylic alcohols were developed using cheap and stable RSO2Na (R = CF3, Ph) as reagents. Various β-trifluoromethyl and sulfonated ketones were obtained in moderate to excellent yields. This strategy provides a facile, direct, and complementary approach to construct all-carbon quaternary stereocenters. In addition, the reaction has the advantages of being chemical oxidant-free and metal-free and has safe and mild reaction conditions.
Absence of Intermediates in the BINOL-Derived Mg(II)/Phosphate-Catalyzed Desymmetrizative Ring Expansion of 1-Vinylcyclobutanols
Capel, Estefania,Rodríguez-Rodríguez, Marta,Uria, Uxue,Pedron, Manuel,Tejero, Tomas,Vicario, Jose L.,Merino, Pedro
supporting information, p. 693 - 707 (2022/01/04)
The catalyzed desymmetrizative ring expansion of alkenylcyclobutanols promoted by halofunctionalization of the alkene moiety with N-bromosuccinimide has been experimentally and computationally studied. The reaction yields highly enantioenriched cyclopenta
Metal-Free Transfer Hydrobromination of C-C Triple Bonds
Chen, Weiqiang,Oestreich, Martin
supporting information, p. 4531 - 4534 (2019/06/27)
A transfer hydrobromination of C-C triple bonds inititated by Br?nsted acids is reported. Hydrogen bromide is released stepwise from a bench-stable cyclohexa-1,4-diene-based surrogate, generating biphenyl and ethylene as waste. A range of vinyl bromides was prepared from terminal and internal, mainly acceptor-substituted alkynes with good functional-group tolerance.
Cyclic Hypervalent Iodine Reagents for Azidation: Safer Reagents and Photoredox-Catalyzed Ring Expansion
Alazet, Sebastien,Preindl, Johannes,Simonet-Davin, Raphael,Nicolai, Stefano,Nanchen, Annik,Meyer, Thierry,Waser, Jerome
supporting information, p. 12334 - 12356 (2018/09/27)
Azides are building blocks of increasing importance in synthetic chemistry, chemical biology, and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its hazardous nature. We introduce two derivatives, tBu-ABX and ABZ (azidobenziodazolone), with a better safety profile, and use them in established photoredox- and metal-mediated azidations, and in a new ring-expansion of silylated cyclobutanols to give azidated cyclopentanones.
A catalytic allylic cation-induced intermolecular allylation-semipinacol rearrangement
Xu, Ming-Hui,Dai, Kun-Long,Tu, Yong-Qiang,Zhang, Xiao-Ming,Zhang, Fu-Min,Wang, Shao-Hua
supporting information, p. 7685 - 7688 (2018/07/15)
A catalytic intermolecular semipinacol rearrangement induced by allylic carbocations has been realized. This tandem reaction is highly efficient under the catalysis of ZnBr2, generating a wide range of α-homoallyl substituted ketones which contain all-carbon quaternary centres in good to excellent yields (up to 98%) with moderate to high diastereoselectivities (up to >20?:?1). Synthetic application of this novel methodology in the construction of core structures of natural products is also reported.
Electrophilic Trifluoromethylthiolation/Semipinacol Rearrangement: Preparation of β-SCF3 Carbonyl Compounds with α-Quaternary Carbon Center
Xi, Chao-Chao,Chen, Zhi-Min,Zhang, Shu-Yu,Tu, Yong-Qiang
supporting information, p. 4227 - 4230 (2018/07/29)
A new and modular electrophilic trifluoromethylthiolation/semipinacol rearrangement of allylic silyl ethers has been developed under mild conditions. This approach allows the formation of a number of β-SCF3 carbonyl compounds with a cyclic and all-carbon quaternary center framework in moderate to good yields. It should be noted that this achievement is a metal-free process and just requires the use of simple acetyl chloride as an acidic promoter. Additionally, an interesting H-migration in competition with aryl-migration process was revealed.
Alkenyl bromides by brominative deoxygenation of ketones in one or two steps
Von Roman,Ruhdorfer,Knorr
, p. 985 - 992 (2007/10/02)
The conversion of ketones into alkenyl bromides is accomplished in one or two steps by 2,2,2-tribromo-2,2-dihydro-1,3,2-benzodioxaphosphole or by the dibromomethyl methyl ether prepared therefrom. Investigations of the scope and limitations provide some hints for the preparative planning and improvement.
Vinyl Cation Intermediates in Solvolytic and Electrophilic Reactions. 1. Solvolysis of α-Arylvinyl Derivatives
Yates, Keith,Mandrapilias, George
, p. 3892 - 3902 (2007/10/02)
The solvolysis of 16 α-arylvinyl tosylates, bromides, and chlorides has been investigated in various alcohol-water mixtures and in acetic acid at several temperatures.All substrates were substituted with either 2-methyl or 2,6-dimethyl groups to accelerate the rates of reaction.The major or exclusive product isolated in most cases was the acetophenone arising from hydrolysis of the expected enol ethers or acetates during workup.The kinetics were simple first order in the vast majority of cases, with excess base added to prevent side reactions.Leaving group effects, Winstein-Grunwald m values, Schleyer Q values, and effects of solvent nucleophilicity all point to a limiting SN1 ionization generating a vinyl cation intermediate, in which there is little rear-side nucleophilic assistance by solvent.Substituent effects led to ρ values in the range -3.9 to -5.3 vs. ?+.Activation parameters are typical for an SN1 process, and ΔS% is insensitive to the presence of zero, one, or two o-methyl groups, as are the effects of solvent polarity on the rates.The results should therefore be directly comparable with other solvolytic or electrophilic reactions generating formally similar vinyl cation intermediates.
