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Bai M, Feng Z, Li J, Tantillo DJ. Bouncing off walls - widths of exit channels from shallow minima can dominate selectivity control. Chem Sci 2020; 11:9937-9944. [PMID: 34094255 PMCID: PMC8162169 DOI: 10.1039/d0sc04036c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A selectivity model based on the widths of pathways to competing products, rather than barrier heights, is formulated for the butadiene + allyl cation reaction. This model was arrived at via analysis of stationary points, intrinsic reaction coordinates, potential energy surface shapes and direct dynamics trajectories, all determined using quantum chemical methods.
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Affiliation(s)
- Mengna Bai
- School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University No. 55 Daxuecheng South Rd., Shapingba Chongqing 401331 China.,Department of Chemistry, University of California Davis One Shields Avenue Davis CA 95616 USA
| | - Zhitao Feng
- Department of Chemistry, University of California Davis One Shields Avenue Davis CA 95616 USA
| | - Jun Li
- School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University No. 55 Daxuecheng South Rd., Shapingba Chongqing 401331 China
| | - Dean J Tantillo
- Department of Chemistry, University of California Davis One Shields Avenue Davis CA 95616 USA
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Krenske EH, Lam S, Ng JPL, Lo B, Lam SK, Chiu P, Houk KN. Concerted Ring Opening and Cycloaddition of Chiral Epoxy Enolsilanes with Dienes. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201503003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Krenske EH, Lam S, Ng JPL, Lo B, Lam SK, Chiu P, Houk KN. Concerted Ring Opening and Cycloaddition of Chiral Epoxy Enolsilanes with Dienes. Angew Chem Int Ed Engl 2015; 54:7422-5. [PMID: 25951012 DOI: 10.1002/anie.201503003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 11/11/2022]
Abstract
Silyl-triflate-catalyzed (4+3) cycloadditions of epoxy enolsilanes with dienes provide a mild and chemoselective synthetic route to seven-membered carbocycles. Epoxy enolsilanes containing a terminal enolsilane and a single stereocenter undergo cycloaddition with almost complete conservation of enantiomeric purity, a finding that argues against the involvement of oxyallyl cation intermediates which have been previously proposed for these types of reactions. Reported are theoretical and experimental investigations of the cycloaddition mechanism. The major enantiomers of the cycloadducts are derived from S(N)2-like reactions of the silylated epoxide with the diene, in which stereospecific ring opening and formation of the two new C-C bonds occur in a single step. Calculations predict, and experiments confirm, that the observed small losses of enantiomeric purity are traced to a triflate-mediated double S(N)2 cycloaddition pathway.
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Affiliation(s)
- Elizabeth H Krenske
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD 4072 (Australia).
| | - Sarah Lam
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (P. R. China)
| | - Jerome P L Ng
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (P. R. China)
| | - Brian Lo
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (P. R. China)
| | - Sze Kui Lam
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (P. R. China)
| | - Pauline Chiu
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (P. R. China).
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA).
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Soriano E, Fernández I. Allenes and computational chemistry: from bonding situations to reaction mechanisms. Chem Soc Rev 2014; 43:3041-105. [DOI: 10.1039/c3cs60457h] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Fernández I, Mascareñas JL. Transition metal-catalysed (4 + 3) cycloaddition reactions involving allyl cations. Org Biomol Chem 2012; 10:699-704. [DOI: 10.1039/c1ob06604h] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Antoline JE, Krenske EH, Lohse AG, Houk KN, Hsung RP. Stereoselectivities and regioselectivities of (4 + 3) cycloadditions between allenamide-derived chiral oxazolidinone-stabilized oxyallyls and furans: experiment and theory. J Am Chem Soc 2011; 133:14443-51. [PMID: 21851070 DOI: 10.1021/ja205700p] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A systematic investigation of the regioselectivities and stereoselectivities of (4 + 3) cycloadditions between unsymmetrical furans and a chiral oxazolidinone-substituted oxyallyl is presented. Cycloadditions were performed using an oxyallyl containing a (R)-4-phenyl-2-oxazolidinone auxiliary (2(Ph)), under either thermal or ZnCl(2)-catalyzed conditions. Reactions of 2(Ph) with 2-substituted furans gave syn cycloadducts selectively, while cycloadditions with 3-substituted furans gave selectively anti cycloadducts. The stereoselectivities were in favor of a single diastereoisomer (I) in all but one case (2-CO(2)R). Density functional theory calculations were performed to explain the selectivities. The results support a mechanism in which all cycloadducts are formed from the E isomer of the oxyallyl (in which the oxazolidinone C═O and oxyallyl oxygen are anti to each other) or the corresponding (E)-ZnCl(2) complex. The major diastereomer is derived from addition of the furan to the more crowded face of the oxyallyl. Crowded transition states are favored because they possess a stabilizing CH-π interaction between the furan and the Ph group.
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Affiliation(s)
- Jennifer E Antoline
- Division of Pharmaceutical Sciences and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53705, USA
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Fernández I, Cossío FP, de Cózar A, Lledós A, Mascareñas JL. Concerted and stepwise mechanisms in metal-free and metal-assisted [4+3] cycloadditions involving allyl cations. Chemistry 2011; 16:12147-57. [PMID: 20839191 DOI: 10.1002/chem.201001714] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The thermal [4+3] cycloaddition reaction between allenes and tethered dienes (1,3-butadiene and furan) assisted by transition metals (Au(I), Au(III), Pd(II), and Pt(II)) was studied computationally within the density functional theory framework and compared to the analogous non-organometallic process in terms of activation barriers, synchronicity and aromaticity of the corresponding transition states. It was found that the metal-mediated cycloaddition reaction is concerted and takes place via transition structures that can be even more synchronous and more aromatic than their non-organometallic analogues. However, the processes exhibit slightly to moderately higher activation barriers than the parent cycloaddition involving the hydroxyallylic cation. The bond polarization induced by the metal moiety is clearly related to the interaction of the transition metal with the allylic π* molecular orbital, which constitutes the LUMO of the initial reactant. Finally, replacement of the 1,3-butadiene by furan caused the transformation to occur stepwise in both the non-organometallic and metal-assisted processes.
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Affiliation(s)
- Israel Fernández
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain.
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Lohse AG, Krenske EH, Antoline JE, Houk KN, Hsung RP. Regioselectivities of (4 + 3) cycloadditions between furans and oxazolidinone-substituted oxyallyls. Org Lett 2010; 12:5506-9. [PMID: 21049917 DOI: 10.1021/ol1023745] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The (4 + 3) cycloadditions of oxazolidinone-substituted oxyallyls and unsymmetrically substituted furans lead to syn regioselectivity when the furan has a 2-Me or 2-COOR substituent, while anti regioselectivity is obtained with a 3-Me or 3-COOR group. DFT calculations are performed to explain the selectivities. The reactivities and regioselectivities are consistent with the ambiphilic reactivity of amino-oxyallyls with furans.
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Affiliation(s)
- Andrew G Lohse
- Division of Pharmaceutical Sciences and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53705, USA
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Harmata M. The (4+3)-cycloaddition reaction: simple allylic cations as dienophiles. Chem Commun (Camb) 2010; 46:8886-903. [PMID: 21057692 DOI: 10.1039/c0cc03620j] [Citation(s) in RCA: 260] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Michael Harmata
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
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Bennacer B, Fujiwara M, Lee SY, Ojima I. Silicon-initiated carbonylative carbotricyclization and [2+2+2+1] cycloaddition of enediynes catalyzed by rhodium complexes. J Am Chem Soc 2005; 127:17756-67. [PMID: 16351104 PMCID: PMC2538960 DOI: 10.1021/ja054221m] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of dodec-11-ene-1,6-diynes or their heteroatom congeners with a hydrosilane catalyzed by Rh(acac)(CO)2 at ambient temperature and pressure of CO gives the corresponding fused 5-7-5 tricyclic products, 5-oxo-1,3a,4,5,7,9-hexahydro-3H-cyclopenta[e]azulenes or their heteroatom congeners, in excellent yields through a unique silicon-initiated cascade carbonylative carbotricyclization (CO-SiCaT) process. It has also been found that the 5-7-5 fused tricyclic products can be obtained from the same type of enediynes and CO through a novel intramolecular [2+2+2+1] cycloaddition process. The characteristics of these two tricyclization processes and the fundamental differences in their reaction mechanisms are discussed. This novel higher-order cycloaddition reaction has also been successfully applied to the tricyclization of undeca-5,10-diyn-1-als, affording the corresponding 5-7-5 fused-ring products bearing a seven-membered lactone moiety. Related [2+2+2] tricyclizations of enediyne and diynal substrates are also discussed. These newly discovered reactions can construct multiple bonds all at once, converting linear starting materials to polycyclic compounds in a single step. Thus, these new processes provide innovative routes to functionalized polycyclic compounds that are useful for the syntheses of natural and unnatural products.
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Affiliation(s)
- Bibia Bennacer
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400
| | - Masaki Fujiwara
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400
| | - Seung-Yub Lee
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400
| | - Iwao Ojima
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400
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Prié G, Prévost N, Twin H, Fernandes SA, Hayes JF, Shipman M. A Lewis Acid Catalyzed Intramolecular [4+3] Cycloaddition Route to Polycyclic Systems That Contain a Seven-Membered Ring. Angew Chem Int Ed Engl 2004; 43:6517-9. [PMID: 15578777 DOI: 10.1002/anie.200461084] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Gildas Prié
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
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Prié G, Prévost N, Twin H, Fernandes SA, Hayes JF, Shipman M. A Lewis Acid Catalyzed Intramolecular [4+3] Cycloaddition Route to Polycyclic Systems That Contain a Seven-Membered Ring. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200461084] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Harmata M, Kahraman M, Adenu G, L. Barnes C. Intramolecular [4+3] Cycloadditions. Towards a Synthesis of Widdrol. HETEROCYCLES 2004. [DOI: 10.3987/com-03-s(p)53] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Chapter 5.3 Five-membered ring systems: Furans and benzofurans. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0959-6380(02)80009-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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