The Experts below are selected from a list of 1902 Experts worldwide ranked by ideXlab platform
Ning Jiao - One of the best experts on this subject based on the ideXlab platform.
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csp2 csp2 bond formation via lewis acid ammonium salt cocatalyzed tandem addition and oxidative dehydrogenation strategy Alkenylation of indoles with α β unsaturated ketones
ChemInform, 2012Co-Authors: Shikai Xiang, Guolin Wu, Ning Jiao, Bo ZhangAbstract:An Alkenylation of indoles at C-3 is developed through tandem addition and oxidative dehydration.
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csp2 csp2 bond formation via lewis acid ammonium salt cocatalyzed tandem addition and oxidative dehydrogenation strategy Alkenylation of indoles with α β unsaturated ketones
Tetrahedron Letters, 2012Co-Authors: Shikai Xiang, Guolin Wu, Ning Jiao, Bo ZhangAbstract:Abstract The Alkenylation of indoles with α,β-unsaturated ketones through a tandem addition and oxidative dehydrogenation strategy has been developed. This method provides an alternative approach for C3 Alkenylation of indoles with α,β-unsaturated ketones. Using inexpensive and readily available BF 3 ·Et 2 O and an ammonium salt as the efficient cocatalyst constitutes the attractive advantage of this reaction.
Yiyun Chen - One of the best experts on this subject based on the ideXlab platform.
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visible light induced alkoxyl radical generation enables selective c sp3 c sp3 bond cleavage and functionalizations
Journal of the American Chemical Society, 2016Co-Authors: Fuyuan Zhang, Hanchu Huang, Yiyun ChenAbstract:The alkoxyl radical is an important reactive intermediate in mechanistic studies and organic synthesis; however, its current generation from alcohol oxidation heavily relies on transition metal activation under strong oxidative conditions. Here we report the first visible-light-induced alcohol oxidation to generate alkoxyl radicals by cyclic iodine(III) reagent catalysis under mild reaction conditions. The β-fragmentation of alkoxyl radicals enables selective C(sp3)–C(sp3) bond cleavage and alkynylation/Alkenylation reactions with various strained cycloalkanols, and for the first time with linear alcohols.
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Visible-Light-Induced Alkoxyl Radical Generation Enables Selective C(sp3)–C(sp3) Bond Cleavage and Functionalizations
2016Co-Authors: Kunfang Jia, Hanchu Huang, Fuyuan Zhang, Yiyun ChenAbstract:The alkoxyl radical is an important reactive intermediate in mechanistic studies and organic synthesis; however, its current generation from alcohol oxidation heavily relies on transition metal activation under strong oxidative conditions. Here we report the first visible-light-induced alcohol oxidation to generate alkoxyl radicals by cyclic iodine(III) reagent catalysis under mild reaction conditions. The β-fragmentation of alkoxyl radicals enables selective C(sp3)–C(sp3) bond cleavage and alkynylation/Alkenylation reactions with various strained cycloalkanols, and for the first time with linear alcohols
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hypervalent iodine reagents enable chemoselective deboronative decarboxylative Alkenylation by photoredox catalysis
Angewandte Chemie, 2015Co-Authors: Hanchu Huang, Kunfang Jia, Yiyun ChenAbstract:Chemoselective C(sp(3))-C(sp(2)) coupling reactions under mild reaction conditions are useful for synthesizing alkyl-substituted alkenes having sensitive functional groups. Reported here is a visible-light-induced chemoselective Alkenylation through a deboronation/decarboxylation sequence under neutral aqueous reaction conditions at room temperature. This reaction represents the first hypervalent-iodine-enabled radical decarboxylative Alkenylation reaction, and a novel benziodoxole-vinyl carboxylic acid reaction intermediate was isolated. This C(sp(3))-C(sp(2)) coupling reaction leads to aryl-and acyl-substituted alkenes containing various sensitive functional groups. The excellent chemoselectivity, stable reactants, and neutral aqueous reaction conditions of the reaction suggest future biomolecule applications.
Keiji Maruoka - One of the best experts on this subject based on the ideXlab platform.
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enantioselective alkynylation of isatin derivatives using a chiral phase transfer transition metal hybrid catalyst system
ACS Catalysis, 2019Co-Authors: Suva Paria, Hyojun Lee, Keiji MaruokaAbstract:An enantioselective alkynylation of isatin derivatives can be realized by using a hybrid catalyst system consisting of chiral phase-transfer catalyst and transition-metal catalyst. The chiral alkynylation products can be used as versatile intermediates for further synthetic transformations.
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Enantioselective Alkynylation of Isatin Derivatives Using a Chiral Phase-Transfer/Transition-Metal Hybrid Catalyst System
2019Co-Authors: Suva Paria, Hyojun Lee, Keiji MaruokaAbstract:An enantioselective alkynylation of isatin derivatives can be realized by using a hybrid catalyst system consisting of chiral phase-transfer catalyst and transition-metal catalyst. The chiral alkynylation products can be used as versatile intermediates for further synthetic transformations
Samir Messaoudi - One of the best experts on this subject based on the ideXlab platform.
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stereoretentive palladium catalyzed arylation Alkenylation and alkynylation of 1 thiosugars and thiols using aminobiphenyl palladacycle precatalyst at room temperature
Chemistry: A European Journal, 2015Co-Authors: Alexandre Bruneau, Jean-daniel Brion, Mouad Alami, Maxime Roche, Abdallah Hamze, Samir MessaoudiAbstract:A general and efficient protocol for the palladium-catalyzed functionalization of mono- and polyglycosyl thiols by using the palladacycle precatalyst G3-XantPhos was developed. The CS bond-forming reaction was achieved rapidly at room temperature with various functionalized (hetero)aryl-, alkenyl-, and alkynyl halides. The functional group tolerance on the electrophilic partner is typically high and anomer selectivities of thioglycosides are high in all cases studied. New sulfur nucleophiles such as thiophenols, alkythiols, and thioaminoacids (cysteine) were also successfully coupled to lead to the most general and practical method yet reported for the functionalization of thiols.
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stereoselective palladium catalyzed Alkenylation and alkynylation of thioglycosides
ChemInform, 2014Co-Authors: Etienne Brachet, Mouad Alami, Jean-daniel Brion, Samir MessaoudiAbstract:A method to prepare thioglycoside derivatives is developed using Pd-catalyzed glycosylation of thioglycosides with alkenyl and alkynyl halides.
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stereoselective palladium catalyzed Alkenylation and alkynylation of thioglycosides
Advanced Synthesis & Catalysis, 2013Co-Authors: Etienne Brachet, Mouad Alami, Jean-daniel Brion, Samir MessaoudiAbstract:An efficient and unprecedented palladium- catalyzed S-glycosylation reaction of a range of al- kenyl and alkynyl halides by using thiosugars as nu- cleophile partners has been established. With palladi- um diacetate in combination with Xantphos as the catalytic system, a variety of b-alkenylthioglycosides as well as b-alkynylthioglycosides can be prepared in good to excellent yields. The efficiency of this gener- al protocol was well-demonstrated by the formal syn- thesis of a leaf-closure b-glucosidase inhibitor.
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pd cu catalyzed direct Alkenylation of azole heterocycles with alkenyl halides
ChemInform, 2011Co-Authors: Sophian Sahnoun, Samir Messaoudi, Jean-daniel Brion, Mouad AlamiAbstract:The use of alkenyl bromides as partners in the direct Pd—Cu-catalyzed C—H Alkenylation of a wide range of heterocycles is described.
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transition metal catalyzed direct c h Alkenylation alkynylation benzylation and alkylation of hetero arenes
European Journal of Organic Chemistry, 2010Co-Authors: Samir Messaoudi, Jean-daniel Brion, Mouad AlamiAbstract:Direct functionalization of (hetero)aromatic C-H bonds has recently emerged as a powerful tool for the functionalization of organic molecules. In the past decade, while many efforts have focused on the direct arylation of (hetero)arenes, much less attention has been devoted to the direct Alkenylation, alkynylation, and benzylation of (hetero)arenes. This micro-review summarizes the development in this area to date, with the focus on how the substrate scope has been expanded through selection of more appropriate synthetic methods, such as the careful choice of catalysts, ligands, bases and reaction conditions.
Aiwen Lei - One of the best experts on this subject based on the ideXlab platform.
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olefinic c h functionalization through radical Alkenylation
Chemical Society Reviews, 2015Co-Authors: Shan Tang, Aiwen Lei, Kun Liu, Chao LiuAbstract:Direct olefinic C–H functionalization represents the ideal way of introducing an alkenyl group into organic molecules. A well-known process is the Heck reaction, which involves alkene insertion and β-hydride elimination in the presence of a transition metal. However, the traditional Heck reaction mainly deals with the Alkenylation of aryl or vinyl electrophiles. Recent developments have revealed that Alkenylation can also be achieved through radical addition to alkenes and following single-electron-transfer (SET) oxidation/elimination. The radical Alkenylation pathway allows Alkenylation with a variety of carbon-centered radicals and even heteroatom-centered radicals. This tutorial review gives an overview of recent advances in this emerging field.
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revealing the metal like behavior of iodine an iodide catalyzed radical oxidative Alkenylation
ChemInform, 2014Co-Authors: Shan Tang, Chao Liu, Wenqing Liao, Ruopeng Bai, Aiwen LeiAbstract:Sulfonyl hydrazides and sulfinates undergo Alkenylation in presence of potassium iodide and tert-butyl hydroperoxide.
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revealing the metal like behavior of iodine an iodide catalysed radical oxidative Alkenylation
Chemical Communications, 2014Co-Authors: Shan Tang, Aiwen Lei, Chao Liu, Wenqing Liao, Ruopeng BaiAbstract:In this work, we have described an alternative Alkenylation approach to illustrate the metal-like behaviour of iodine in cross-coupling reactions. Alkenylation could proceed through iodide catalysed radical initiation, radical addition and iodine promoted alkenyl functionality recovery. Catalytic HI elimination similar to the β-hydride elimination of transition metals was realized for the radical Alkenylation of sulfonyl hydrazides. Operando IR and cyclic voltammetry experiments were carried out to confirm the crucial role of iodine in the radical Alkenylation process.
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alkynylation of α halocarbonyl compounds a stille type cross coupling for the formation of c sp c sp3 bonds under neutral conditions
ChemInform, 2007Co-Authors: Wei Shi, Chao Liu, Aiwen LeiAbstract:A direct alkynylation of readily available α-halo esters and amides with high yields is described herein; a distinct switch from diyne formation to alkynylation products was attained under neutral conditions.