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Gang Li Tao Wang Fan Fei Dr. Yi‐Ming Su Dr. Yan Li Dr. Quan Lan Prof. Dr. Xi‐Sheng Wang 《Angewandte Chemie (International ed. in English)》2016,55(10):3491-3495
The first example of nickel‐catalyzed decarboxylative fluoroalkylation of α,β‐unsaturated carboxylic acids has been developed with commonly available fluoroalkyl halides. This novel transformation has demonstrated broad substrate scope, excellent functional‐group tolerance, mild reaction conditions, and excellent stereoselectivity. Mechanistic investigations indicate that a fluoroalkyl radical is involved in the catalytic cycle. 相似文献
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A Copper(I)‐Catalyzed Enantioselective γ‐Boryl Substitution of Trifluoromethyl‐Substituted Alkenes: Synthesis of Enantioenriched γ,γ‐gem‐Difluoroallylboronates 下载免费PDF全文
Dr. Ryoto Kojima Sota Akiyama Prof. Dr. Hajime Ito 《Angewandte Chemie (International ed. in English)》2018,57(24):7196-7199
The first catalytic enantioselective γ‐boryl substitution of CF3‐substituted alkenes is reported. A series of CF3‐substituted alkenes was treated with a diboron reagent in the presence of a copper(I)/Josiphos catalyst to afford the corresponding optically active γ,γ‐gem‐difluoroallylboronates in high enantioselectivity. The thus obtained products could be readily converted into the corresponding difluoromethylene‐containing homoallylic alcohols using highly stereospecific allylation reactions. 相似文献
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《中国化学》2018,36(1):55-58
Highly regiodivergent copper‐catalyzed allylic/propargylic difluoromethylation reactions by employing different ligands are described. When 5,6‐dimethyl‐1,10‐phenanthroline was used as the ligand, exclusively α‐difluoromethylated products were obtained, while γ‐selective difluoromethylated products were generated when N‐heterocyclic carbene‐SIPr was used as the ligand. Likewise, high α‐ vs. γ‐selectivities were achieved in the presence of similar copper catalysts for the reactions of propargyl bromides. Moreover, a copper‐catalyzed asymmetric allylic difluoromethylation reaction with moderate to good enantioselectivity by the use of chiral ligands was developed. 相似文献
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Enantioselective Palladium‐Catalyzed Oxidative β,β‐Fluoroarylation of α,β‐Unsaturated Carbonyl Derivatives 下载免费PDF全文
Javier Miró Dr. Carlos del Pozo Prof. F. Dean Toste Prof. Santos Fustero 《Angewandte Chemie (International ed. in English)》2016,55(31):9045-9049
The site‐selective palladium‐catalyzed three‐component coupling of deactivated alkenes, arylboronic acids, and N‐fluorobenzenesulfonimide is disclosed herein. The developed methodology establishes a general, modular, and step‐economical approach to the stereoselective β‐fluorination of α,β‐unsaturated systems. 相似文献
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Copper‐Catalyzed Enantioselective Allyl–Allyl Coupling between Allylic Boronates and Phosphates with a Phenol/N‐Heterocyclic Carbene Chiral Ligand 下载免费PDF全文
Yuto Yasuda Prof. Dr. Hirohisa Ohmiya Prof. Dr. Masaya Sawamura 《Angewandte Chemie (International ed. in English)》2016,55(36):10816-10820
Copper‐catalyzed enantioselective allyl–allyl coupling between allylboronates and either Z‐acyclic or cyclic allylic phosphates using a new chiral N‐heterocyclic carbene ligand, bearing a phenolic hydroxy, is reported. This reaction occurs with exceptional SN2′‐type regioselectivities and high enantioselectivities to deliver chiral 1,5‐diene derivatives with a tertiary stereogenic center at the allylic/homoallylic position. 相似文献
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Qian Wang Chuanfa Ni Mingyou Hu Qiqiang Xie Qinghe Liu Shitao Pan Jinbo Hu 《Angewandte Chemie (International ed. in English)》2020,59(22):8507-8511
A Cu‐catalyzed gem‐bis(trifluoromethyl)olefination of α‐diazo esters, using TMSCF3 as the only fluorocarbon source, has been developed and provides an exquisite method to access gem‐bis(trifluoromethyl)alkenes. This unprecedented olefination process involves a carbene migratory insertion into “CuCF3” to generate the α‐CF3‐substituted organocopper species, which then undergoes β‐fluoride elimination and two consecutive addition‐elimination processes to give the desired products. The key to this efficient one‐pot C1‐to‐C3 synthetic protocol lies in the controllable double (over single and triple) trifluoromethylations of the gem‐difluoroalkene intermediates. 相似文献
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Copper‐Catalyzed γ‐Selective and Stereospecific Allylic Cross‐Coupling with Secondary Alkylboranes 下载免费PDF全文
Yuto Yasuda Kazunori Nagao Yoshinori Shido Prof. Dr. Seiji Mori Prof. Dr. Hirohisa Ohmiya Prof. Dr. Masaya Sawamura 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9666-9670
The scope of the copper‐catalyzed coupling reactions between organoboron compounds and allylic phosphates is expanded significantly by employing triphenylphosphine as a ligand for copper, allowing the use of secondary alkylboron compounds. The reaction proceeds with complete γ‐E‐selectivity and preferential 1,3‐syn stereoselectivity. The reaction of γ‐silicon‐substituted allylic phosphates affords enantioenriched α‐stereogenic allylsilanes. 相似文献
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Construction of Quaternary Stereogenic Carbon Centers through Copper‐Catalyzed Enantioselective Allylic Cross‐Coupling with Alkylboranes 下载免费PDF全文
Kentaro Hojoh Yoshinori Shido Prof. Dr. Hirohisa Ohmiya Prof. Dr. Masaya Sawamura 《Angewandte Chemie (International ed. in English)》2014,53(19):4954-4958
A combination of an in situ generated chiral CuI/DTBM‐MeO‐BIPHEP catalyst system and EtOK enabled the enantioselective SN2′‐type allylic cross‐coupling between alkylborane reagents and γ,γ‐disubstituted primary allyl chlorides with enantiocontrol at a useful level. The reaction generates a stereogenic quaternary carbon center having three sp3‐alkyl groups and a vinyl group. This protocol allowed the use of terminal alkenes as nucleophile precursors, thus representing a formal reductive allylic cross‐coupling of terminal alkenes. A reaction pathway involving addition/elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed. 相似文献
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Direct Catalytic Asymmetric Vinylogous Conjugate Addition of Unsaturated Butyrolactones to α,β‐Unsaturated Thioamides 下载免费PDF全文
Dr. Liang Yin Dr. Hisashi Takada Shaoquan Lin Dr. Naoya Kumagai Prof. Dr. Masakatsu Shibasaki 《Angewandte Chemie (International ed. in English)》2014,53(21):5327-5331
Soft Lewis acid/Brønsted base cooperative catalysts have enabled direct catalytic asymmetric vinylogous conjugate addition of α,β‐ and β,γ‐unsaturated butyrolactones to α,β‐unsaturated thioamides with perfect atom economy. When using α‐angelica lactone and its derivatives as pronucleophiles, as little as 0.5 mol % catalyst loading was sufficient to complete the reaction necessary to construct consecutive tri‐ and tetrasubstituted stereogenic centers in a highly diastereo‐ and enantioselective fashion. 相似文献
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Highly Regio‐ and Enantioselective Synthesis of N‐Substituted 2‐Pyridones: Iridium‐Catalyzed Intermolecular Asymmetric Allylic Amination 下载免费PDF全文
Xiao Zhang Ze‐Peng Yang Lin Huang Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2015,54(6):1873-1876
The first iridium‐catalyzed intermolecular asymmetric allylic amination reaction with 2‐hydroxypyridines has been developed, thus providing a highly efficient synthesis of enantioenriched N‐substituted 2‐pyridone derivatives from readily available starting materials. This protocol features a good tolerance of functional groups in both the allylic carbonates and 2‐hydroxypyridines, thereby delivering multifunctionalized heterocyclic products with up to 98 % yield and 99 % ee. 相似文献
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Trifluoromethylthiolation and Trifluoromethylselenolation of α‐Diazo Esters Catalyzed by Copper 下载免费PDF全文
Christian Matheis Prof. Dr. Lukas J. Goossen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12270-12273
α‐Diazo esters are smoothly converted into the corresponding trifluoromethyl thio‐ or selenoethers by reaction with Me4NSCF3 or Me4NSeCF3, respectively, in the presence of catalytic amounts of copper thiocyanate. This straightforward method gives high yields under neutral conditions at room temperature and is applicable to a wide range of functionalized molecules, including diverse α‐amino acid derivatives. It is well‐suited for the late‐stage introduction of trifluoromethylthio or ‐seleno groups into drug‐like molecules. 相似文献
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N‐Heterocyclic Carbene Catalyzed Cyclocondensation of α,β‐Unsaturated Carboxylic Acids: Enantioselective Synthesis of Pyrrolidinone and Dihydropyridinone Derivatives 下载免费PDF全文
Xiang‐Yu Chen Zhong‐Hua Gao Chun‐Yu Song Chun‐Lin Zhang Prof. Dr. Zhi‐Xiang Wang Prof. Dr. Song Ye 《Angewandte Chemie (International ed. in English)》2014,53(43):11611-11615
The catalytic cyclocondensation of in situ activated α,β‐unsaturated carboxylic acids was developed. N‐heterocyclic carbenes efficiently catalyzed the generation of α,β‐unsaturated acyl azolium intermediates from α,β‐unsaturated carboxylic acids via in situ generated mixed anhydrides for the enantioselective [3+2] and [3+3] cyclocondensation with α‐amino ketones and alkyl(aryl)imines, respectively. The corresponding pyrrolidinones and dihydropyridinones were isolated in good yields with high to excellent enantioselectivities. 相似文献