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Zhang ZB, Yang Y, Yu ZX, Xia JB. Lewis Base-Catalyzed Amino-Acylation of Arylallenes via C–N Bond Cleavage: Reaction Development and Mechanistic Studies. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01000] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Zheng-Bing Zhang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), University of Chinese Academy of Sciences, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yusheng Yang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Zhi-Xiang Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Ji-Bao Xia
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), University of Chinese Academy of Sciences, Chinese Academy of Sciences, Lanzhou 730000, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Swamy KCK, Anitha M, Debnath S, Shankar M. Reactivity of allenylphosphonates/allenylphosphine oxides – some new addition/cycloaddition and cyclization pathways. PURE APPL CHEM 2019. [DOI: 10.1515/pac-2018-1111] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Abstract
In this paper, we highlight some addition/cycloaddition reactions of allenylphosphonates and allenylphosphine oxides, mostly based on the work done in our laboratory. Thus the electrophilic addition of iodine monochloride (ICl) with allenylphosphine oxides affords cyclic phosphonium salts rather than γ-chloro-β-iodovinylphosphine oxides (NMR, HRMS, X-ray) that exhibit rather unusual downfield shifts in the 31P NMR spectra. These compounds undergo hydrolysis to afford γ-hydroxy-β-iodovinylphosphine oxides; the hydroxymethyl group in these compounds can be oxidized by Dess-Martin periodinane to afford the corresponding aldehyde-substituted vinylphosphine oxides. A [2+2] cycloaddition product of an allenylphosphonate has also been structurally characterized. Other reactions that are highlighted include those leading to (Z)/(E)-β-aminovinylphosphonates, β-ketophosphonates (and their utility in Horner-Wadsworth-Emmons reaction), indolyl/furanyl/isocoumaranyl/naphthyl phosphine oxides, thiophosphorylated phosphonates and azo-substituted coumarin phosphonates.
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Affiliation(s)
- K. C. Kumara Swamy
- School of Chemistry , University of Hyderabad , Hyderabad-500046, Telangana , India
| | - Mandala Anitha
- School of Chemistry , University of Hyderabad , Hyderabad-500046, Telangana , India
| | - Shubham Debnath
- School of Chemistry , University of Hyderabad , Hyderabad-500046, Telangana , India
| | - Mallepalli Shankar
- School of Chemistry , University of Hyderabad , Hyderabad-500046, Telangana , India
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3
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Anitha M, Kumara Swamy KC. Highly functionalised (γ-azido/γ-fluoro-β-iodo/)vinyl derivatives from phosphorus based allenes or allenoates: I⋯O halogen bonding interactions. Org Biomol Chem 2019; 17:5736-5748. [DOI: 10.1039/c9ob00715f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
γ-Azido/γ-fluoro-β-iodo-vinyl phosphine oxides/phosphonates/esters/sulphone and a γ-diodoallene were synthesised from phosphorus-based allenes or allenoates or a sulphur based allene; in many cases, I⋯O halogen bonding is observed in the solid state.
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Affiliation(s)
- Mandala Anitha
- School of Chemistry
- University of Hyderabad
- Hyderabad 500 046
- India
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4
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Yang B, Qiu Y, Bäckvall JE. Control of Selectivity in Palladium(II)-Catalyzed Oxidative Transformations of Allenes. Acc Chem Res 2018; 51:1520-1531. [PMID: 29792667 DOI: 10.1021/acs.accounts.8b00138] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxidation reactions play a central role in organic synthesis, and it is highly desirable that these reactions are mild and occur under catalytic conditions. In Nature, oxidation reactions occur under mild conditions via cascade processes, and furthermore, they often occur in an enantioselective manner with many of them involving molecular oxygen or hydrogen peroxide as the terminal oxidant. Inspired by the reactions in Nature, we have developed a number of Pd(II)-catalyzed cascade reactions under mild oxidative conditions. These reactions have an intrinsic advantage of step economy and rely on selectivity control in each step. In this Account, we will discuss the control of chemo-, regio-, and diastereoselectivity in Pd(II)-catalyzed dehydrogenative cascade coupling reactions. The enantioselective version of this methodology has also been addressed, and new chiral centers have been introduced using a catalytic amount of a chiral phosphoric acid (CPA). Research on this topic has provided access to important compounds attractive for synthetic and pharmaceutical chemists. These compounds include carbocyclic, heterocyclic, and polycyclic systems, as well as polyunsaturated open-chain structures. Reactions leading to these compounds are initiated by coordination of an allene and an unsaturated π-bond moiety, such as olefin, alkyne, or another allene, to the Pd(II) center, followed by allene attack involving a C(sp3)-H cleavage under mild reaction conditions. Recent progress within our research group has shown that weakly coordinating groups (e.g., hydroxyl, alkoxide, or ketone) could also initiate the allene attack on Pd(II), which is essential for the oxidative carbocyclization. Furthermore, a highly selective palladium-catalyzed allenic C(sp3)-H bond oxidation of allenes in the absence of an assisting group was developed, which provides a novel and straightforward synthesis of [3]dendralene derivatives. For the oxidative systems, benzoquinone (BQ) and its derivatives are commonly used as oxidants or catalytic co-oxidants (electron transfer mediators, ETMs) together with molecular oxygen. A variety of transformations including carbocyclization, acetoxylation, arylation, carbonylation, borylation, β-hydride elimination, alkynylation, alkoxylation, and olefination have been demonstrated to be compatible with this Pd(II)-based catalytic oxidative system. Recently, several challenging synthetic targets, such as cyclobutenes, seven-membered ring carbocycles, spirocyclic derivatives, functional cyclohexenes, and chiral cyclopentenone derivatives were obtained with high selectivity using these methods. The mechanisms of the reactions were mainly studied by kinetic isotope effects (KIEs) or DFT computations, which showed that in most cases the C(sp3)-H cleavage is the rate-determining step (RDS) or partially RDS. This Account will describe our efforts toward the development of highly selective and atom-economic palladium(II)-catalyzed oxidative transformation of allenes (including enallenes, dienallenes, bisallenes, allenynes, simple allenes, and allenols) with a focus on overcoming the selectivity problem during the reactions.
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Affiliation(s)
- Bin Yang
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Youai Qiu
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Jan-E. Bäckvall
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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5
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Zhao Z, Murphy GK. Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes. Beilstein J Org Chem 2018; 14:796-802. [PMID: 29719576 PMCID: PMC5905278 DOI: 10.3762/bjoc.14.67] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 03/22/2018] [Indexed: 11/23/2022] Open
Abstract
Allyl and vinyl chlorides represent important structural motifs in organic chemistry. Herein is described the chemoselective and regioselective reaction of aryl- and α-substituted phenylallenes with the hypervalent iodine (HVI) reagent 1-chloro-1,2-benziodoxol-3-one. The reaction typically results in vicinal dichlorides, except with proton-containing α-alkyl substituents, which instead give chlorinated dienes as the major product. Experimental evidence suggests that a radical mechanism is involved.
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Affiliation(s)
- Zhensheng Zhao
- Department of Chemistry, University of Waterloo, 200 University Ave. W., Waterloo, N2L3G1, ON, Canada
| | - Graham K Murphy
- Department of Chemistry, University of Waterloo, 200 University Ave. W., Waterloo, N2L3G1, ON, Canada
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6
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Cresswell AJ, Eey STC, Denmark SE. Catalytic, Stereoselective Dihalogenation of Alkenes: Challenges and Opportunities. Angew Chem Int Ed Engl 2015; 54:15642-82. [PMID: 26630449 PMCID: PMC5072131 DOI: 10.1002/anie.201507152] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Indexed: 11/09/2022]
Abstract
Although recent years have witnessed significant advances in the development of catalytic, enantioselective halofunctionalizations of alkenes, the related dihalogenation of olefins to afford enantioenriched vicinal dihalide products remains comparatively underdeveloped. However, the growing number of complex natural products bearing halogen atoms at stereogenic centers has underscored this critical gap in the synthetic chemist's arsenal. This Review highlights the selectivity challenges inherent in the design of enantioselective dihalogenation processes, and formulates a mechanism-based classification of alkene dihalogenations, including those that may circumvent the "classical" haliranium (or alkene-dihalogen π-complex) intermediates. A variety of metal and main group halide reagents that have been used for the dichlorination or dibromination of alkenes are discussed, and the proposed mechanisms of these transformations are critically evaluated.
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Affiliation(s)
| | - Stanley T-C Eey
- Organic Chemistry, Institute of Chemical and Engineering Sciences, A*STAR, Singapore 138667 (Singapore)
| | - Scott E Denmark
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (USA) http://www.scs.illinois.edu/denmark.
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7
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Katalytische stereoselektive Dihalogenierung von Alkenen: Herausforderungen und Chancen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507152] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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8
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Cai ZJ, Yang C, Wang SY, Ji SJ. Palladium-catalyzed highly regioselective 6-exo-dig cyclization and alkenylation of ortho-ethynylanilides: the synthesis of polyene-substituted benzo[d][1,3]oxazines. Chem Commun (Camb) 2015; 51:14267-70. [DOI: 10.1039/c5cc06510k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A Pd-catalyzed highly regioselective 6-exo-dig cyclization/alkenylation reaction of ortho-ethynylanilides has been developed.
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Affiliation(s)
- Zhong-Jian Cai
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
| | - Chao Yang
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
| | - Shun-Yi Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
| | - Shun-Jun Ji
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science & Collaborative Innovation Center of Suzhou Nano Science and Technology
- Soochow University
- Suzhou
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9
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Chen D, Chen X, Lu Z, Cai H, Shen J, Zhu G. Palladium-Catalyzed Dienylation of Haloalkynes using 2,3-Butadienyl Acetates: A Facile Access to (1Z)-1,2-Dihalo- 3-vinyl-1,3-dienes. Adv Synth Catal 2011. [DOI: 10.1002/adsc.201100113] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Poli G, Prestat G, Liron F, Kammerer-Pentier C. Selectivity in Palladium-Catalyzed Allylic Substitution. TOP ORGANOMETAL CHEM 2011. [DOI: 10.1007/3418_2011_14] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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11
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Nakamura I, Yamamoto Y. Transition-Metal-Catalyzed Reactions in Heterocyclic Synthesis. Chem Rev 2004; 104:2127-98. [PMID: 15137788 DOI: 10.1021/cr020095i] [Citation(s) in RCA: 1302] [Impact Index Per Article: 65.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Itaru Nakamura
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
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12
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Zhao L, Lu X. Palladium(II)-catalyzed three-component coupling reaction initiated by acetoxypalladation of alkynes: an efficient route to gamma,delta-unsaturated carbonyls. Org Lett 2002; 4:3903-6. [PMID: 12599488 DOI: 10.1021/ol026741h] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[formula: see text] A divalent palladium-catalyzed coupling reaction of electron-deficient alkynes and acrolein or MVK (methyl vinyl ketone) was developed. The reaction provides an efficient method to synthesize gamma,delta-unsaturated carbonyls. A mechanism involving acetoxypalladation of alkyne, followed by insertion of alkene and protonolysis of the C-Pd bond, is proposed. The protonolysis of the carbon-palladium bond with the assistance of bidentate nitrogen containing ligands is the key step in this tandem reaction.
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Affiliation(s)
- Ligang Zhao
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China
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13
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Alcaide B, Almendros P, Aragoncillo C. Additions of allenyl/propargyl organometallic reagents to 4-oxoazetidine-2-carbaldehydes: novel palladium-catalyzed domino reactions in allenynes. Chemistry 2002; 8:1719-29. [PMID: 11933100 DOI: 10.1002/1521-3765(20020402)8:7<1719::aid-chem1719>3.0.co;2-u] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Metal-mediated carbonyl allenylation and propargylation of 4-oxoazetidine-2-carbaldehydes were investigated in aqueous environment. Different propargyl bromide and metal promoters showed varied regio- and stereoselectivities on product formation. In addition, an unprecedented one-pot stereoselective synthesis of beta-chlorinated allylic alcohols, which can also be considered as functionalized allylsilanes, has been developed, which involves tin(IV) chloride-mediated reaction of propargyltrimethylsilane and 4-oxoazetidine-2-carbaldehydes. Some of the resulting coupling products were submitted to transition metal catalyzed reactions, such as the allenic Pauson-Khand and palladium-catalyzed reactions, leading to novel fused or bridged tricyclic beta-lactams. Remarkably, a novel domino process, namely the allene cyclization/intramolecular Heck reaction was found. A likely mechanism for the cascade reaction should involve an intramolecular cyclization on a (pi-allyl)palladium complex and a Heck-type reaction.
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Affiliation(s)
- Benito Alcaide
- Departamento de Química Orgánica I Facultad de Química Universidad Complutense de Madrid, 28040 Madrid, Spain.
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14
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Löfstedt J, Franzén J, Bäckvall JE. Carbon-carbon bond formation in regio- and stereoselective palladium-catalyzed cyclization of allene-substituted conjugated dienes. J Org Chem 2001; 66:8015-25. [PMID: 11722199 DOI: 10.1021/jo0157324] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Regio- and stereoselective palladium-catalyzed reactions of allene-substituted 1,3-dienes 1 in acetic acid at room temperature lead to cyclization with formation of a carbon-carbon bond between the middle carbon of the allene and the terminal carbon of the 1,3-diene. Two different types of reactions, both that constitute 1,4-carboacetoxylations of the 1,3-diene, have been developed. In one of the reactions, Pd(II) catalyzes the oxidation of 1 to bicyclic compounds 2, and in the other, Pd(0) catalyzes the transformation of 1 to bicyclic compounds 3. The products 2 are useful for further synthetic transformations and undergo Diels-Alder reactions with dienophiles to give polycyclic ring systems.
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Affiliation(s)
- J Löfstedt
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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15
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Horváth A, Bäckvall JE. Palladium(II)-catalyzed S(N)2' reactions of alpha-allenic acetates. Stereoconvergent synthesis of (Z,E)-2-bromo-1,3-dienes. J Org Chem 2001; 66:8120-6. [PMID: 11722214 DOI: 10.1021/jo015950x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of acetylated alpha-allenic alcohols with LiBr in the presence of 1.5 mol % of Pd(OAc)(2) provides easy access to substituted (Z,E)-2-bromo-1,3-dienes in good yields with excellent diastereoselectivity. Both secondary and tertiary acetates as well as terminal and nonterminal allenes were studied to investigate the scope and the limitations of the reaction. A mechanism is proposed to clarify how a diastereomeric mixture of the starting compound is transformed into a single diastereomer of the product.
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Affiliation(s)
- A Horváth
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden
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16
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Liu G, Lu X. Palladium(II)-catalyzed tandem reaction of intramolecular aminopalladation of allenyl N-tosylcarbamates and conjugate addition. Org Lett 2001; 3:3879-82. [PMID: 11720559 DOI: 10.1021/ol016727p] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A divalent palladium-catalyzed tandem cyclization-coupling reaction of allenyl N-tosylcarbamates and acrolein was developed. The reaction gave aldehyde-functionalized 2-oxazolidinones in one step with high regioselectivity. A mechanism involving intramolecular aminopalladation of allene, followed by insertion of alkene and C-Pd bond protonolysis, is proposed. [reaction: see text]
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Affiliation(s)
- G Liu
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China
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17
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Jonasson C, Horváth A, Bäckvall JE. Intramolecular Palladium(II)-Catalyzed 1,2-Addition to Allenes. J Am Chem Soc 2000. [DOI: 10.1021/ja001748k] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Catrin Jonasson
- Contribution from the Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Attila Horváth
- Contribution from the Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Jan-E. Bäckvall
- Contribution from the Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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18
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Jonasson C, Karstens WF, Hiemstra H, Bäckvall JE. Palladium(II)-catalyzed intramolecular 1,2-oxidation of allenes involving nitrogen nucleophiles. Tetrahedron Lett 2000. [DOI: 10.1016/s0040-4039(99)02343-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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19
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Ishikura M, Matsuzaki Y, Agata I, Katagiri N. A concise access to 2-allenylindole derivatives based on the palladium catalyzed cross-coupling reaction of indolylborates. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00861-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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20
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The manganese-mediated regioselective chlorination of allenes in synthetic approaches towards the spongistatins and halomon natural products. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(98)01410-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Schlama T, Baati R, Gouverneur V, Valleix A, Falck JR, Mioskowski C. Totalsynthese von (±)-Halomon über eine Johnson-Claisen-Umlagerung. Angew Chem Int Ed Engl 1998. [DOI: 10.1002/(sici)1521-3757(19980803)110:15<2226::aid-ange2226>3.0.co;2-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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22
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23
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24
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Hayashi M, Saigo K. Palladium-Catalyzed Regioselective Bis-Alkynylation of Propargylic Carbonates: Synthesis of Enediyne Compounds. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)01435-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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