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Yagci BB, Donmez SE, Şahin O, Türkmen YE. Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles. Beilstein J Org Chem 2023; 19:66-77. [PMID: 36741815 PMCID: PMC9874235 DOI: 10.3762/bjoc.19.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023] Open
Abstract
We have developed a catalytic aza-Nazarov reaction of N-acyliminium salts generated in situ from the reaction of a variety of cyclic and acyclic imines with α,β-unsaturated acyl chlorides to afford substituted α-methylene-γ-lactam heterocycles. The reactions proceed effectively in the presence of catalytic (20 mol %) amounts of AgOTf as an anion exchange agent or hydrogen-bond donors such as squaramides and thioureas as anion-binding organocatalysts. The aza-Nazarov cyclization of 3,4-dihydroisoquinolines with α,β-unsaturated acyl chlorides gives tricyclic lactam products 7 in up to 79% yield with full diastereocontrol (dr = >99:1). The use of acyclic imines in a similar catalytic aza-Nazarov reaction with 20 mol % of AgOTf results in the formation of α-methylene-γ-lactam heterocycles 19 in up to 76% yield and with good to high diastereoselectivities (4.3:1 to 16:1). We have demonstrated the scalability of the reaction with a gram-scale example. The relative stereochemistry of the α-methylene-γ-lactam products 19 has been determined via the single-crystal X-ray analysis of lactam 19l. In order to shed light on the details of the reaction mechanism, we have performed carefully designed mechanistic studies which consist of experiments on the effect of β-silicon stabilization, the alkene geometry of the α,β-unsaturated acyl chloride reactants, and adventitious water on the success of the catalytic aza-Nazarov reaction.
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Affiliation(s)
- Bilge Banu Yagci
- Department of Chemistry, Faculty of Science, Bilkent University, Ankara 06800, Turkey
| | - Selin Ezgi Donmez
- Department of Chemistry, Faculty of Science, Bilkent University, Ankara 06800, Turkey
| | - Onur Şahin
- Department of Occupational Health & Safety, Faculty of Health Sciences, Sinop University, Sinop 57000, Turkey
| | - Yunus Emre Türkmen
- Department of Chemistry, Faculty of Science, Bilkent University, Ankara 06800, Turkey
- UNAM – National Nanotechnology Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey
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2
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Chiu HC, See XY, Tonks IA. Dative Directing Group Effects in Ti-Catalyzed [2+2+1] Pyrrole Synthesis: Chemo- and Regioselective Alkyne Heterocoupling. ACS Catal 2019; 9:216-223. [PMID: 31768294 DOI: 10.1021/acscatal.8b04669] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Transient dative substrate-Ti interactions have been found to play a key role in controlling the regioselectivity of alkyne insertion and [2+2] cycloaddition in Ti-catalyzed [2+2+1] pyrrole synthesis and Ti-catalyzed alkyne hydroamination. TMS-protected alkynes with pendent Lewis basic groups can invert the regioselectivity of TMS-protected alkyne insertion, leading to the selective formation of highly substituted 3-TMS pyrroles. The competency of various potential directing groups was investigated, and it was found that the directing-group effect can be tuned by modifying the catalyst Lewis acidity, the directing-group basicity, or the directing-group tether length. Dative directing-group effects are unexplored with Ti catalysts, and this study demonstrates the potential power of dative substrate-Ti interactions in tuning selectivity.
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Affiliation(s)
- Hsin-Chun Chiu
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Xin Yi See
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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3
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Sun Z, Hu S, Huo Y, Wang Z. Titanium tetrachloride-mediated synthesis of N-aryl-substituted azacycles from cyclic ethers. RSC Adv 2017. [DOI: 10.1039/c6ra27325d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Five- and six-membered N-aryl-substituted azacycles were synthesized from amines and cyclic ethers under mild conditions while no expensive metal reagent was required.
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Affiliation(s)
- Zunming Sun
- State Key Laboratory and Institute of Elemento-Organic Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Shanshan Hu
- State Key Laboratory and Institute of Elemento-Organic Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Yan Huo
- State Key Laboratory and Institute of Elemento-Organic Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Zhihong Wang
- State Key Laboratory and Institute of Elemento-Organic Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
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4
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Huo C, Yuan Y. Brønsted Acid-Catalyzed Three-Component Reaction of Anilines, α-Oxoaldehydes, and α-Angelicalactone for the Synthesis of Complex Pyrrolidones. J Org Chem 2015; 80:12704-10. [DOI: 10.1021/acs.joc.5b02354] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Congde Huo
- Key Laboratory
of Eco-Environment-Related
Polymer Materials Ministry of Education, College of Chemistry and
Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China
| | - Yong Yuan
- Key Laboratory
of Eco-Environment-Related
Polymer Materials Ministry of Education, College of Chemistry and
Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China
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5
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Kumar A, Shah BA. Synthesis of Biaryls via Benzylic C–C Bond Cleavage of Styrenes and Benzyl Alcohols. Org Lett 2015; 17:5232-5. [DOI: 10.1021/acs.orglett.5b02578] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Arvind Kumar
- Academy of Scientific
and Innovative Research and Natural
Product Microbes, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu-Tawi 180001, India
| | - Bhahwal Ali Shah
- Academy of Scientific
and Innovative Research and Natural
Product Microbes, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu-Tawi 180001, India
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6
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Micalizio GC, Hale SB. Reaction design, discovery, and development as a foundation to function-oriented synthesis. Acc Chem Res 2015; 48:663-73. [PMID: 25668752 DOI: 10.1021/ar500408e] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Convergent C-C bond-forming reactions define the fabric of organic synthesis and, when applied in complex molecule synthesis, can have a profound impact on efficiency by decreasing the longest linear sequence of transformations required to convert simple starting materials to complex targets. Despite their well-appreciated strategic significance, campaigns in natural product synthesis typically embrace only a small suite of reactivity to achieve such bond construction (i.e., nucleophilic addition to polarized π-bonds, nucleophilic substitution, cycloaddition, and metal-catalyzed "cross-coupling"), therefore limiting the sites at which convergent coupling chemistry can be strategically employed. In our opinion, it is far too often that triumphs in the field are defined by chemical sequences that do not address the challenges associated with discovery, development, and production of natural product-inspired agents. We speculated that advancing an area of chemical reactivity not represented in the few well-established strategies for convergent C-C bond formation may lead to powerful new retrosynthetic relationships that could simplify approaches to the syntheses of a variety of different classes of natural products. Our studies ultimately embraced the pursuit of strategies to control the course of metallacycle-mediated "cross-coupling" between substrates containing sites of simple π-unsaturation (ubiquitous functionality in organic chemistry including alkenes, alkynes, allenes, aldehydes, and imines, among others). In just eight years since our initial publication in this area, we have defined over 20 stereoselective intermolecular C-C bond-forming reactions that provide access to structural motifs of relevance for the synthesis of polyketides, fatty acids, alkaloids, and terpenes, while doing so in a direct and stereoselective fashion. These achievements continue to serve as the foundation of my group's activity in natural product and function-oriented synthesis, where our achievements in reaction development are challenged in the context of complex targets. Among our early efforts, we achieved the most concise synthesis of a benzoquinone ansamycin ever described (macbecin I), and moved beyond this achievement to explore the role of our chemistry in function-oriented synthesis targeting the discovery of natural product-inspired Hsp90 inhibitors. These later efforts have led to the discovery of a uniquely selective benzoquinone ansamycin-inspired Hsp90 inhibitor that lacks the problematic quinone present in the natural series. This achievement was made possible by a concise chemical synthesis pathway that had at its core the application of metallacycle-mediated cross-coupling chemistry.
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Affiliation(s)
- Glenn C. Micalizio
- Department of Chemistry,
Burke Laboratory, Dartmouth College, Hanover, New Hampshire 03755, United States
| | - Sarah B. Hale
- Department of Chemistry,
Burke Laboratory, Dartmouth College, Hanover, New Hampshire 03755, United States
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7
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Loose F, Plettenberg I, Haase D, Saak W, Schmidtmann M, Schäfer A, Müller T, Beckhaus R. Aromatic Imines in the Titanocene Coordination Sphere—Titanaaziridine vs 1-Aza-2-titanacyclopent-4-ene Structures. Organometallics 2014. [DOI: 10.1021/om500750y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Florian Loose
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Inka Plettenberg
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Detlev Haase
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Wolfgang Saak
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Marc Schmidtmann
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - André Schäfer
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
| | - Rüdiger Beckhaus
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Federal Republic of Germany
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8
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Chen C, Hu J, Su J, Tong X. Synthesis of substituted γ-lactam via Pd(0)-catalyzed cyclization of alkene-tethered carbamoyl chloride. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.04.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Li L, Kristian KE, Han A, Norton JR, Sattler W. Synthesis, Structural Characterization, and Reactivity of Cp2- and (CpMe)2-Ligated Titanaaziridines and Titanaoxiranes with Fast Enantiomer Interconversion Rates. Organometallics 2012. [DOI: 10.1021/om300825n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ling Li
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Kathleen E. Kristian
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Arthur Han
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Jack R. Norton
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Wesley Sattler
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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10
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Lv H, Tiwari B, Mo J, Xing C, Chi YR. Highly Enantioselective Addition of Enals to Isatin-Derived Ketimines Catalyzed by N-Heterocyclic Carbenes: Synthesis of Spirocyclic γ-Lactams. Org Lett 2012; 14:5412-5. [DOI: 10.1021/ol302475g] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hui Lv
- Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Bhoopendra Tiwari
- Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Junming Mo
- Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Chong Xing
- Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Yonggui Robin Chi
- Division of Chemistry & Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
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11
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Chou SSP, Wu CJJ. Ring opening of dihydro-2-pyridones and intramolecular Diels–Alder reactions. Tetrahedron 2012. [DOI: 10.1016/j.tet.2011.11.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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12
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Yang D, Micalizio GC. Convergent and stereodivergent synthesis of complex 1-aza-7-oxabicyclo[2.2.1]heptanes. J Am Chem Soc 2011; 133:9216-9. [PMID: 21604673 DOI: 10.1021/ja202900h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A convergent and stereodivergent pathway to highly substituted 1-aza-7-oxabicyclo[2.2.1]heptanes is described. It begins with a coupling reaction involving allylic alcohol, aldehyde, and LiHMDS to produce stereodefined primary homoallylic amines. Subsequent N-oxidation and condensation with formaldehyde or glyoxylate defines a convenient entry to densely functionalized homoallylic nitrones whose intramolecular annulation can be controlled to deliver one of two distinct heterocyclic skeletons, each with ≥20:1 stereoselection. Control of the stereochemistry in these reactions results from both control of the nitrone geometry and selective partitioning of the reaction pathway between direct [3 + 2] cycloaddition and tandem [3,3] rearrangement/[3 + 2] cycloaddition.
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Affiliation(s)
- Dexi Yang
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA
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13
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Generation of quaternary centers by reductive cross-coupling: shifting of regioselectivity in a subset of allylic alcohol-based coupling reactions. Tetrahedron Lett 2011; 52:2144-2147. [PMID: 21666832 DOI: 10.1016/j.tetlet.2010.11.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Regioselective titanium alkoxide-mediated reductive cross-coupling reactions of allylic alcohols with vinylsilanes and imines have previously been demonstrated to proceed with allylic transposition by formal metallo-[3,3]-rearrangement [thought to proceed by a sequence of: 1) directed carbometalation, and 2) syn-elimination]. While many examples have been described that support this reaction path, a collection of substrates have recently been identified that react by way of an alternative pathway, delivering a concise convergent route to coupled products bearing a quaternary center.
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14
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Reichard HA, Micalizio GC. Metallacycle-Mediated Cross-Coupling with Substituted and Electronically Unactivated Alkenes. Chem Sci 2011; 4:573-589. [PMID: 21436986 DOI: 10.1039/c0sc00394h] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This perspective surveys the history of- and recent advances in- metallacycle-mediated coupling chemistry of substituted alkenes. While the reaction of preformed metal-π complexes with ethylene was reported nearly 30 years ago, the generalization of this mode of bimolecular C-C bond formation to the regio- and stereoselective union of complex substrates has only recently begun to emerge. This perspective discusses early observations in this area, the challenges associated with controlling such processes, the evolution of a general strategy to overcome these challenges, and a summary of highly regio- and stereoselective convergent coupling reactions that are currently available by metallacycle-mediated cross-coupling with substituted alkenes.
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Affiliation(s)
- Holly A Reichard
- The Department of Chemistry, The Scripps Research Institute; Scripps-Florida, 130 Scripps Way #3A2, Jupiter, FL 33418, USA. ; Tel: 561 228 2463;
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15
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Chen MZ, McLaughlin M, Takahashi M, Tarselli MA, Yang D, Umemura S, Micalizio GC. Preparation of stereodefined homoallylic amines from the reductive cross-coupling of allylic alcohols with imines. J Org Chem 2010; 75:8048-59. [PMID: 21069994 PMCID: PMC2993781 DOI: 10.1021/jo101535d] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Regio-, diastereo-, and enantioselective coupling reactions between imines and allylic alcohols have been developed. These coupling reactions deliver complex homoallylic amine products through a convergent C-C bond forming process that does not proceed through intermediate allylic organometallic reagents. In general, convergent coupling, by exposure of an allylic alkoxide to a preformed Ti-imine complex, occurs with allylic transposition in a predictable and stereocontrolled manner. While simple diastereoselection in these reactions is high, delivering anti-products with ≥20:1 selectivity, the organometallic transformation described is compatible with a diverse range of functionality and substrates (including aliphatic and aromatic imines, allylic silanes, trisubstituted alkenes, vinyl- and aryl halides, trifluoromethyl groups, thioethers, and aromatic heterocycles). Alkene geometry of the products is a complex function of the allylic alcohol structure and is consistent with a mechanistic proposal based on syn-carbometalation followed by syn-elimination by way of a boat-like transition state geometry. Single asymmetric coupling reactions provide a means to translate the stereochemical information of the allylic alcohol to the homoallylic amine or to control diastereoselection in the coupling reactions of achiral allylic alcohols with chiral imines. Double asymmetric coupling reactions are also described that afford a unique means to control stereoselection in these complex convergent coupling processes. Finally, empirical models are proposed that are consistent with the observed stereochemical course of these coupling reactions en route to chiral homoallylic amines possessing di- or trisubstituted alkenes and anti- or syn- relative stereochemistry at the allylic and homoallylic positions.
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Affiliation(s)
- Ming Z. Chen
- Kellogg School of Science and Technology at The Scripps Research Institute
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16
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Synthesis of pyrrolidin-2-ones via tandem reactions of vinyl sulfonium salts under mild conditions. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.07.108] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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17
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Barlan AU, Micalizio GC. The regio- and stereochemical course of reductive cross-coupling reactions between 1,3-disubstituted allenes and vinylsilanes: Synthesis of ( Z)-dienes. Tetrahedron 2010; 66:4775-4783. [PMID: 24031099 PMCID: PMC3769195 DOI: 10.1016/j.tet.2010.02.062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In investigations aimed at exploring the potential of disubstituted allenes in stereoselective synthesis, we report studies that explore the reductive cross-coupling reaction of vinylsilanes with a range of substituted allenes. Regiochemical control is attained by employing allenic alkoxides, where the proximal heteroatom dictates the site-selectivity in a process that proceeds by net formal metallo-[3,3] rearrangement (directed carbometalation/elimination). Stereoselectivity in these reactions is complex, with both the nature of allene substitution and relative stereochemistry of the substrate impacting the stereoselective generation of each alkene of a substituted 1,3-diene. 2009 Elsevier Ltd. All rights reserved.
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Affiliation(s)
- Allan U Barlan
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458
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