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To TA, Phan NTA, Mai BK, Nguyen TV. Controlling the regioselectivity of the bromolactonization reaction in HFIP. Chem Sci 2024; 15:7187-7197. [PMID: 38756818 PMCID: PMC11095382 DOI: 10.1039/d4sc01503g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 04/09/2024] [Indexed: 05/18/2024] Open
Abstract
The halolactonization reaction provides rapid access to densely functionalized lactones from unsaturated carboxylic acids. The endo/exo regioselectivity of this cyclization reaction is primarily determined by the electronic stabilization of alkene substituents, thus making it inherently dependent on substrate structures. Therefore this method often affords one type of halolactone regioisomer only. Herein, we introduce a simple and efficient method for regioselectivity-switchable bromolactonization reactions mediated by HFIP solvent. Two sets of reaction conditions were developed, each forming endo-products or exo-products in excellent regioselectivity. A combination of computational and experimental mechanistic studies not only confirmed the crucial role of HFIP, but also revealed the formation of endo-products under kinetic control and exo-products under thermodynamic control. This study paves the way for future work on the use of perfluorinated solvents to dictate reaction outcomes in organic synthesis.
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Affiliation(s)
- Tuong Anh To
- School of Chemistry, University of New South Wales Sydney NSW 2052 Australia
| | - Nhu T A Phan
- School of Chemistry, University of New South Wales Sydney NSW 2052 Australia
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh Pennsylvania 15260 USA
| | - Thanh Vinh Nguyen
- School of Chemistry, University of New South Wales Sydney NSW 2052 Australia
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2
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Ghosh D, Samal AK, Parida A, Ikbal M, Jana A, Jana R, Sahu PK, Giri S, Samanta S. Progress in Electrochemically Empowered C-O Bond Formation: Unveiling the Pathway of Efficient Green Synthesis. Chem Asian J 2024:e202400116. [PMID: 38584137 DOI: 10.1002/asia.202400116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/12/2024] [Accepted: 04/04/2024] [Indexed: 04/09/2024]
Abstract
(C-X) bonds (X=C, N, O) are the main backbone for making different skeleton in the organic synthetic transformations. Among all the sustainable techniques, electro-organic synthesis for C-X bond formation is the advanced tool as it offers a greener and more cost-effective approach to chemical reactions by utilizing electrons as reagents. In this review, we want to explore the recent advancements in electrochemical C-O bond formation. The electrochemically driven C-O bond formation represents an emerging and exciting area of research. In this context, electrochemical techniques offers numerous advantages, including higher yields, cost-efficient production, and simplified work-up procedures. This method enables the continuous and consistent formation of C-O bonds in molecules, significantly enhancing overall reaction yields. Furthermore, both intramolecular and intermolecular C-O bond forming reaction provided valuable products of O-containing acyclic/cyclic analogue. Hence, carbonyl (C=O), ether -O-), and ester (-COOR) functionalization in both cyclic/acyclic analogues have been prepared continuously via this innovative pathway. In this context, we want to discuss one-decade electrochemical synthetic pathways of various C-O bond contains functional group in chronological manner. This review focused on all the synthetic aspects including mechanistic path and has also mentioned overall critical finding regarding the C-O bond formation via electrochemical pathways.
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Affiliation(s)
- Debosmit Ghosh
- Department of Chemistry, Bidhannagar College, Kolkata, 700064, India
| | - Aroop Kumar Samal
- Department of Chemistry, C.V. Raman Global UniversityInstitution, Bhubaneswar, 752054, India
| | - Anita Parida
- Department of Chemistry, C.V. Raman Global UniversityInstitution, Bhubaneswar, 752054, India
| | - Mohammed Ikbal
- Department of Chemistry, Berhampore Girls' College, Berhampore, 742101, India
| | - Akash Jana
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Kolkata, Mohanpur741246, India
| | - Rathin Jana
- Department of Chemistry, Shahid Matangini Hazra Govt. General Degree College for women, West Bengal, India
| | - Pradeepta Kumar Sahu
- Department of Chemistry, C.V. Raman Global UniversityInstitution, Bhubaneswar, 752054, India
| | - Soumen Giri
- Department of Chemistry, C.V. Raman Global UniversityInstitution, Bhubaneswar, 752054, India
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3
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Paul S, Choudhuri T, Das S, Pratap R, Bagdi AK. Tunable Regioselective Allylic Alkylation/Iodination of Imidazoheterocycles in Water. J Org Chem 2024; 89:1492-1504. [PMID: 38215401 DOI: 10.1021/acs.joc.3c02091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024]
Abstract
The switchable roles of allylic alcohol and molecular iodine as reagents and catalysts have been demonstrated in the regioselective allylic alkylation and iodination of imidazoheterocycles employing the mixture of allylic alcohol-I2. First, we have explored the catalytic activity of iodine for the allylation of imidazoheterocycles using allylic alcohol in an aqueous medium. The allylation of a library of imidazoheterocycles and other electron-rich heterocycles like indole, pyrazole, 4-hydroxy coumarin, and 6-amino uracil has been achieved by employing this methodology. The efficiency of the I2 catalyst for N-allylation of azoles has also been demonstrated. Next, we have shown that this mixture of allylic alcohol and I2 could be beneficial for the iodination of imidazoheterocycles under room temperature. Mechanistic studies indicate that the activation of allylic alcohol by molecular iodine took place probably through halogen bonding, and NMR studies show that the reaction did not proceed through allylic ether formation.
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Affiliation(s)
- Suvam Paul
- Department of Chemistry, University of Kalyani, Kalyani 741235, India
| | | | - Sourav Das
- Department of Chemistry, University of Kalyani, Kalyani 741235, India
| | - Ramendra Pratap
- Department of Chemistry, University of Delhi, New Delhi 110007, India
| | - Avik Kumar Bagdi
- Department of Chemistry, University of Kalyani, Kalyani 741235, India
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4
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Li Y, Zhao C, Wang Z, Zeng Y. Halogen Bond Catalysis: A Physical Chemistry Perspective. J Phys Chem A 2024; 128:507-527. [PMID: 38214658 DOI: 10.1021/acs.jpca.3c06363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
As important noncovalent interactions, halogen bonds have been widely used in material science, supramolecular chemistry, medicinal chemistry, organocatalysis, and other fields. In the past 15 years, halogen bond catalysis has become a developed field in organocatalysis for the catalysts' advantages of being environmentally friendly, inexpensive, and recyclable. Halogen bonds can induce various organic reactions, and halogen bond catalysis has become a powerful alternative to the fully explored hydrogen bond catalysis. From a physical chemistry view, this perspective provides an overview of the latest progress and key examples of halogen bond catalysis via activation of the lone pair systems of organic functional group, π systems, and metal complexes. The research progresses in halogen bond catalysis by our group were also introduced.
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Affiliation(s)
- Ying Li
- College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Chang Zhao
- College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Zhuo Wang
- College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Yanli Zeng
- College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, China
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5
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Suresh S, Chien HS, Chen CH, Tsai HY, Chung DR, Kavala V, Yao CF. Iodine-Catalyzed Regioselective Synthesis of Diphenyl-Substituted Carbazoles via [4 + 2] Annulation of β-Formyl Ketones with Indoles. J Org Chem 2023. [PMID: 38032287 DOI: 10.1021/acs.joc.3c01857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
The [4 + 2] annulation of β-formyl ketones with an indole has been developed for the regioselective synthesis of diphenyl-substituted carbazoles in the presence of a catalytic amount of iodine. The 1,4-dicarbonyl compound containing a phenyl group at the α-position of an aldehyde group reacts more readily with indoles to form carbazole derivatives. Using this method, a variety of carbazole derivatives can be readily accessed under mild reaction conditions.
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Affiliation(s)
- Sundaram Suresh
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
| | - Hung-Sheng Chien
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
| | - Chao-Hua Chen
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
| | - Hao-Yu Tsai
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
| | - Dai-Ru Chung
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
| | - Veerababurao Kavala
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
| | - Ching-Fa Yao
- Department of Chemistry, National Taiwan Normal University, No. 88, Sec. 4, Ting-Zhou Rd, Taipei 11677, Taiwan R. O. C
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6
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Shinde J, Kavala V, Yao CF. Pd-Catalyzed Regioselective (Markovnikov) Addition of Aryl Boronic Acids to Terminal Alkynes of 1,3-Dicarbonyl Compounds and Cyclization/Debenzoylation of Olefinic Dicarbonyl: Access to Arylated Pyran and ( E)-4-Methylene-1,6-diphenylhex-5-en-1-one. Org Lett 2023; 25:6943-6948. [PMID: 37713283 DOI: 10.1021/acs.orglett.3c02192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
This Letter outlines palladium-catalyzed regioselective (Markovnikov's) addition of aryl boronic acids to propargyl 1,3-dicarbonyl alkyne to accomplish olefinic/diene 1,3-dicarbonyl compounds without the need for water workup. This methodology showcases remarkable performance with wide-ranging substrate diversity, achieving high yields while employing merely 3 mol % [Pd] alongside a mild KOAc base. Moreover, the utility of dicarbonyl olefins is exemplified through their application in intramolecular cyclization and debenzoylation reactions to access valuable trisubstituted pyran building blocks and (E)-4-methylene-1,6-diphenylhex-5-en-1-one synthesis.
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Affiliation(s)
- Jivan Shinde
- Department of Chemistry National Taiwan Normal University 88, Sec. 4, Ting-Zhou Road, Taipei 116, Taiwan R.O.C
| | - Veerababurao Kavala
- Department of Chemistry National Taiwan Normal University 88, Sec. 4, Ting-Zhou Road, Taipei 116, Taiwan R.O.C
| | - Ching-Fa Yao
- Department of Chemistry National Taiwan Normal University 88, Sec. 4, Ting-Zhou Road, Taipei 116, Taiwan R.O.C
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7
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Steparuk EV, Meshcheryakova EA, Viktorova VV, Ulitko MV, Obydennov DL, Sosnovskikh VY. Oxidative Ring-Opening Transformation of 5-Acyl-4-pyrones as an Approach for the Tunable Synthesis of Hydroxylated Pyrones and Furans. J Org Chem 2023; 88:11590-11602. [PMID: 37504952 DOI: 10.1021/acs.joc.3c00907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
A selective and tunable approach for oxidation of 4-pyrones has been developed via ring-opening transformations leading to various hydroxylated oxaheterocycles. The first step of the strategy includes the base-catalyzed epoxidation of 5-acyl-4-pyrones in the presence of hydrogen peroxide for the effective synthesis of pyrone epoxides in high yields. The epoxides bearing the CO2Et group are reactive molecules that can undergo both pyrone and oxirane ring-opening via deformylation to produce hydroxylated 2-pyrones or 4-pyrones. The acid-promoted transformation led to 3-hydroxy-4-pyrones (24-76% yields), whereas the K2CO3-catalyzed ring-opening process of 2-carbethoxy-4-pyrone epoxides proceeded as an attack of alcohol at the C-3 position bearing the CO2Et group to give functionalized 6-acyl-5-hydroxy-2-pyrones (27-87% yields). The base-catalyzed reaction of 2-aryl-4-pyrone epoxides was followed by ring contraction and the dearoylation process to produce 3-hydroxyfuran-2-carbaldehydes in 42-80% yields. The transformation of 3-aroylchromone epoxides led to flavonols and 3-hydroxybenzofuran-2-carbaldehyde in the acidic and basic conditions, respectively. The prepared hydroxylated heterocycles demonstrated high reactivity for further transformations and low cytotoxicity and are promising fluorophores or UV filters.
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Affiliation(s)
- Elena V Steparuk
- Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation
| | - Ekaterina A Meshcheryakova
- Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation
| | - Viktoria V Viktorova
- Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation
| | - Maria V Ulitko
- Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation
| | - Dmitrii L Obydennov
- Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation
| | - Vyacheslav Y Sosnovskikh
- Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation
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8
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Díaz-Salazar H, Rodríguez-Colín JC, Vazquez-Chavez J, Hernández-Rodríguez M. The Chameleonic Nature of the Nitro Group Applied to a Base-Promoted Cascade Reaction To Afford Indane-Fused Dihydrofurans. J Org Chem 2023; 88:8150-8162. [PMID: 37341114 DOI: 10.1021/acs.joc.3c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
We disclose a Michael/Conia-ene/SN2 cascade reaction for the synthesis of Indane-fused dihydrofurans from 1,3-dicarbonyl compounds and 2-alkynylnitrostyrenes promoted by potassium carbonate in DMSO at room temperature. In this reaction, the nitro group has a chameleonic role, first as an electron-withdrawing group for the Michael addition, then the nitronate behaves as a nucleophile, and finally, the allylic nitro acts as a leaving group. The product is obtained as a single diastereomer, affording up to 82% with 1,3-keto esters and 58% with 1,3-diketones. Furthermore, DFT calculations of the reaction mechanism explained the chemoselective addition of the nitronate over the enolate to the unactivated triple bond, with the enolate addition being highly endothermic.
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Affiliation(s)
- Howard Díaz-Salazar
- Instituto de Química, Universidad Nacional Autónoma de México Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Cd. Mx., México
| | - Juan Carlos Rodríguez-Colín
- Instituto de Química, Universidad Nacional Autónoma de México Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Cd. Mx., México
| | - Josué Vazquez-Chavez
- Instituto de Química, Universidad Nacional Autónoma de México Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Cd. Mx., México
| | - Marcos Hernández-Rodríguez
- Instituto de Química, Universidad Nacional Autónoma de México Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Cd. Mx., México
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9
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Zhu BH, Ye SB, Nie ML, Xie ZY, Wang YB, Qian PC, Sun Q, Ye LW, Li L. I 2 -Catalyzed Cycloisomerization of Ynamides: Chemoselective and Divergent Access to Indole Derivatives. Angew Chem Int Ed Engl 2023; 62:e202215616. [PMID: 36573021 DOI: 10.1002/anie.202215616] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Indexed: 12/28/2022]
Abstract
Herein, an I2 -catalyzed unprecedented cycloisomerization of ynamides is developed, furnishing various functionalized bis(indole) derivatives in generally good to excellent yields with wide substrate scope and excellent atom-economy. This protocol not only represents the first molecular-iodine-catalyzed tandem complex alkyne cycloisomerizations, but also constitutes the first chemoselective cycloisomerization of tryptamine-ynamides involving distinctively different C(sp3 )-C(sp3 ) bond cleavage and rearrangement. Moreover, chiral tetrahydropyridine frameworks containing two stereocenters are obtained with moderate to excellent diastereoselectivities and excellent enantioselectivities. Meanwhile, cycloisomerization and aromatization of ynamides produce pyrrolyl indoles with high efficiency enabled by I2 . Additionally, control experiments and theoretical calculations reveal that this reaction probably undergoes a tandem 5-exo-dig cyclization/rearrangement process.
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Affiliation(s)
- Bo-Han Zhu
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China
| | - Sheng-Bing Ye
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China
| | - Min-Ling Nie
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China
| | - Zhong-Yang Xie
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China
| | - Yi-Bo Wang
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China
| | - Peng-Cheng Qian
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China
| | - Qing Sun
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China
| | - Long-Wu Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Long Li
- College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035, China.,Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000, China.,State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
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10
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Shichijo K, Watanabe M, Hisaeda Y, Shimakoshi H. Development of Visible Light-Driven Hybrid Catalysts Composed of Earth Abundant Metal Ions Modified TiO 2 and B 12 Complex. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20220080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Keita Shichijo
- Department of Applied Chemistry, Graduated School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395
| | - Midori Watanabe
- Center of Advanced Instrumental Analysis, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395
| | - Yoshio Hisaeda
- Department of Applied Chemistry, Graduated School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395
| | - Hisashi Shimakoshi
- Department of Applied Chemistry, Graduated School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395
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11
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Tian S, Xie H, Zhang H, Fu S. Efficient separation of acetylated cellulose from eucalyptus and its enhancement on the mechanical strength of polylactic acid. Int J Biol Macromol 2021; 191:100-107. [PMID: 34537292 DOI: 10.1016/j.ijbiomac.2021.09.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/02/2021] [Accepted: 09/12/2021] [Indexed: 10/20/2022]
Abstract
A simplified and green strategy was provided for the synthesis of cellulose acetate. Cellulose acetate (CA) was isolated from the directly acetylated eucalyptus powder after hydrothermal treatment to selectively remove hemicellulose without delignification. The conversion rate of cellulose (90.75%) and the yield of the acetylated product (61.34%) were greatly improved by hydrothermal treatment, while the re-condensation of lignin during hydrothermal treatment made no adverse difference. The characterization results verified that the acetylated product was cellulose acetate with uniform molecular weight, good thermal stability and semi-crystalline structure. Moreover, CA was used to reinforce polylactic acid (PLA) films prepared by solvent casting. The PLA-CA composite with 5 wt% CA showed an increase of 80.63% in tensile strength and 59.51% in Young's modulus, and their density decreased from 1.2427 g/cm3 to 1.0028 g/cm3. The lightweight and excellent mechanical properties promote the application potential of biodegradable composites to replace petroleum-based plastics.
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Affiliation(s)
- Shenglong Tian
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Guangdong Province 510640, China
| | - Huihui Xie
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Guangdong Province 510640, China
| | - Hui Zhang
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Guangdong Province 510640, China
| | - Shiyu Fu
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Guangdong Province 510640, China.
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12
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Zhang J, Luo J, Li X, Zhang Q, Wu Z, Lan Y, Wei D. Insights into Organoamine-Catalyzed Asymmetric Synthesis of Axially Chiral Allenoates Using Morita-Baylis-Hillman Carbonates and Trisubstituted Allenoates: Mechanism and Origin of Stereoselectivity. J Org Chem 2021; 86:15276-15283. [PMID: 34605241 DOI: 10.1021/acs.joc.1c01871] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A computational study was performed to explore the possible mechanisms of β-isocinchonine-catalyzed asymmetric C(sp2)-H allylation of trisubstituted allenoates using Morita-Baylis-Hillman (MBH) carbonates for synthesis of axially chiral tetrasubstituted allenoates. The calculated results indicate that the most energetically favorable pathway includes (1) nucleophilic attack on MBH carbonate by β-isocinchonine, (2) BocO- dissociation, (3) stereoselective formation of the C-C bond, and (4) regeneration of the catalyst. By tracking the orbital overlap/interaction changes, the half shoulder-to-head orbital overlap mode can be smoothly switched to a head-to-head orbital overlap mode for the key C-C σ bond formation, which is also identified as the stereoselectivity-determining process. Further distortion/interaction, noncovalent interaction (NCI), and atom-in-molecule (AIM) analyses demonstrate that C-H···O and C-H···π interactions should be key for controlling the axial and central chirality. This work would be useful for rational design of organocatalytic allylic alkylation reactions for synthesis of axially chiral compounds in the future.
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Affiliation(s)
- Jiaming Zhang
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
| | - Jing Luo
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
| | - Xue Li
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
| | - Qiaoyu Zhang
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
| | - Zhoujie Wu
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
| | - Yu Lan
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
| | - Donghui Wei
- The College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan 450001, P.R. China
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