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Yang J, Park Y, Yang S, Lee G, Ha MW, Kim MH, Hong S, Park HG. Enantioselective Total Synthesis of Nitraria Alkaloids: (+)-Nitramine, (+)-Isonitramine, (-)-Isonitramine, and (-)-Sibirine via Asymmetric Phase-Transfer Catalytic α-Allylations of α-Carboxylactams. J Org Chem 2021; 86:4375-4390. [PMID: 33464902 DOI: 10.1021/acs.joc.0c02573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many optically active 2-azaspirocyclic structures have frequently been found in biologically active natural products. In particular, Nitraria alkaloids, (+)-nitramine, (+)-isonitramine, (-)-isonitramine, and (-)-sibirine, have stereogenicity on their quaternary carbon of the 2-azaspiro[5,5]undecane-7-ol structure. To synthesize Nitraria alkaloids, we developed a new enantioselective synthetic method for chiral α-quaternary lactams via the α-alkylation of α-tert-butoxycarbonyl lactams. α-Alkylation of α-tert-butoxycarboxylactams in the circumstances of phase-transfer catalytic (PTC) system (solid KOH, toluene, and -40 °C) by virtue of the catalytic action of (S,S)-NAS bromide (5 mol %) furnished the corresponding α-alkyl-α-tert-butoxycarbonyl lactams in very high chemical (<99%) and enantioselectivity (<98% ee). Our catalytic methodology was successfully applied for the enantioselective total synthesis of Nitraria alkaloids. (+)-Isonitramine was obtained in 12 steps (98% ee, 43% yield) from δ-valerolactam through enantioselective phase-transfer catalytic allylation, Dieckmann condensation, and diastereoselective reduction as the key reactions. (-)-Sibirine and (+)-nitramine were prepared from (-)-isonitramine or its intermediate. Switching the phase-transfer catalyst from (S,S)-NAS bromide to (R,R)-NAS bromide afforded (-)-isonitramine (98% ee, 41% yield). (-)-Sibirine was synthesized by N-ethoxycarbonylation of (-)-isonitramine followed by reduction (98% ee, 14 steps, 32% yield). Furthermore, the diastereoselective reduction of (R)-2-benzhydryl-2-azaspiro[5.5]undecane-1,7-dione [(R)-15] followed by reductive removal of the diphenylmethyl group successfully gave (+)-nitramine (98% ee, 11 steps, 40% yield).
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Affiliation(s)
- Jewon Yang
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Yohan Park
- College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae, Gyeongnam 50834, Republic of Korea
| | - Sehun Yang
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Geumwoo Lee
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Min Woo Ha
- College of Pharmacy, Jeju National University, 102 Jejudaehak-ro Jeju 63243, Republic of Korea
| | - Mi-Hyun Kim
- College of Pharmacy, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon 21936, Republic of Korea
| | - Suckchang Hong
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hyeung-Geun Park
- Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
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2
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Affiliation(s)
- Zhiping Yin
- School of Pharmacy, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Jian-Xing Xu
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Xiao-Feng Wu
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, People’s Republic of China
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3
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Fukuyama T, Okada T, Nakashima N, Ryu I. Radical Mediated Aza‐
Pauson‐Khand
Reaction of Acetylenes, Imines, and CO Leading to Five‐Membered Unsaturated Lactams. Helv Chim Acta 2019. [DOI: 10.1002/hlca.201900186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Takahide Fukuyama
- Department of Chemistry, Graduate School of ScienceOsaka Prefecture University, Sakai Osaka 599-8531 Japan
| | - Takuma Okada
- Department of Chemistry, Graduate School of ScienceOsaka Prefecture University, Sakai Osaka 599-8531 Japan
| | - Nao Nakashima
- Department of Chemistry, Graduate School of ScienceOsaka Prefecture University, Sakai Osaka 599-8531 Japan
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of ScienceOsaka Prefecture University, Sakai Osaka 599-8531 Japan
- Department of Applied ChemistryNational Chiao Tung University Hsinchu 30010 Taiwan
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4
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Matsubara H, Kawamoto T, Fukuyama T, Ryu I. Applications of Radical Carbonylation and Amine Addition Chemistry: 1,4-Hydrogen Transfer of 1-Hydroxylallyl Radicals. Acc Chem Res 2018; 51:2023-2035. [PMID: 30137961 DOI: 10.1021/acs.accounts.8b00278] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
1,4-Hydrogen transfer from the 1-hydroxyallyl radical to give the enoxyl (α-keto) radical is an exothermic process with a high activation energy based on DFT calculations. The lack of experimental examples of such 1,4-H shift reactions lies in the difficulty of generating the 1-hydroxyallyl radical. We have shown that radical carbonylation of alkenyl radicals with CO followed by nucleophilic trapping of the carbonyl portion of the resulting radical by amines gives rise to 1-amino-substituted 1-hydroxyallyl radicals in situ. At the outset of this chemistry, we examined intramolecular trapping reactions via radical carbonylation of alkynylamines mediated by tributyltin hydride. Consequently, α-methylene lactams were obtained, for which the initially formed 1-amino-substituted 1-hydroxyallyl radical underwent a 1,4-H shift followed by subsequent β-scission, which led to the expulsion of a tributyltin radical. A competing pathway of the 1,4-H shift of 1-amino-substituted 1-hydroxyallyl radicals involving hydrogen abstraction was observed, which led to the formation of α-stannylmethylene lactams as a major byproduct. However, in contrast, when intermolecular trapping of α-ketenyl radicals by amines was carried out, the 1,4-H shift from the 1-amino-substituted 1-hydroxyallyl radical became the major pathway, which gave good yields of α,β-unsaturated amides. Thus, we were able to develop three-component reactions comprising terminal alkynes, CO, and amines that led to α,β-unsaturated amides via the 1,4-H shift reaction. DFT calculations support the observation that the 1,4-H shift is more facile when 1-hydroxyallyl radicals have both 1-amino and 3-tin substituents. The choice of substituents on the amine nitrogen is also important, since N-C bond cleavage via an SH2-type reaction can become a competing pathway. Such an unusual SH2-type reaction at the amine nitrogen is favored when the leaving alkyl radicals are stable, such as PhC(•)H(CH3) and t-Bu•. Interestingly, even nucleophilic attack of tertiary amines onto α-ketenyl radicals causes cleavage of the C-N bond. For this reaction, DFT calculations predict an indirect homolytic substitution mechanism involving expulsion of alkyl radicals through the zwitterionic radical intermediate arising from nucleophilic amine addition onto the α-ketenyl radical. In contrast, the carbonylation of aryl radicals, generated from aryl iodides, in the presence of amines gave aromatic carboxylic amides in good yields. It is proposed that radical anions originating from acyl radicals and amines undergo electron transfer to aryl iodides to give aminocarbonylation products.
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Affiliation(s)
- Hiroshi Matsubara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takuji Kawamoto
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan 300, ROC
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5
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Matsubara H, Kawamoto T, Fukuyama T, Ryu I. Theoretical Calculations for the 1,4-Hydrogen Shift of 1-Hydroxyallyl Radicals Leading to α-Keto Radicals; Prediction of Facilitation by 1-Amino and 3-Tin Substituents. CHEM LETT 2018. [DOI: 10.1246/cl.180522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hiroshi Matsubara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takuji Kawamoto
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
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Guo SH, Wang MY, Pan GF, Zhu XQ, Gao YR, Wang YQ. Synthesis of Monofluoromethylthioesters from Aldehydes. Adv Synth Catal 2018. [DOI: 10.1002/adsc.201800136] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Shi-Huan Guo
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education; Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 People's Republic of China
| | - Meng-Yue Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education; Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 People's Republic of China
| | - Gao-Fei Pan
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education; Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 People's Republic of China
| | - Xue-Qing Zhu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education; Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 People's Republic of China
| | - Ya-Ru Gao
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education; Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 People's Republic of China
| | - Yong-Qiang Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education; Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 People's Republic of China
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7
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Guo SH, Zhang XL, Pan GF, Zhu XQ, Gao YR, Wang YQ. Synthesis of Difluoromethylthioesters from Aldehydes. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201710731] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shi-Huan Guo
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Xing-Long Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Gao-Fei Pan
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Xue-Qing Zhu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Ya-Ru Gao
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Yong-Qiang Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
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8
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Guo SH, Zhang XL, Pan GF, Zhu XQ, Gao YR, Wang YQ. Synthesis of Difluoromethylthioesters from Aldehydes. Angew Chem Int Ed Engl 2018; 57:1663-1667. [DOI: 10.1002/anie.201710731] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/28/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Shi-Huan Guo
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Xing-Long Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Gao-Fei Pan
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Xue-Qing Zhu
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Ya-Ru Gao
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
| | - Yong-Qiang Wang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science; Northwest University; Xi'an 710069 P.R. China
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9
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Affiliation(s)
- Ilhyong Ryu
- Graduate School of Sciences, Osaka Prefecture University
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10
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Teng F, Sun S, Jiang Y, Yu JT, Cheng J. Copper-catalyzed oxidative C(sp3)–H/N–H coupling of sulfoximines and amides with simple alkanes via a radical process. Chem Commun (Camb) 2015; 51:5902-5. [DOI: 10.1039/c5cc00839e] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A copper-catalyzed oxidative C(sp3)–H/N–H coupling of sulfoximines and amides with simple alkanes via a radical pathway was developed.
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Affiliation(s)
- Fan Teng
- School of Petrochemical Engineering
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Jiangsu Province Key Laboratory of Fine Petrochemical Engineering
- Changzhou University
- Changzhou 213164
| | - Song Sun
- School of Petrochemical Engineering
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Jiangsu Province Key Laboratory of Fine Petrochemical Engineering
- Changzhou University
- Changzhou 213164
| | - Yan Jiang
- School of Petrochemical Engineering
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Jiangsu Province Key Laboratory of Fine Petrochemical Engineering
- Changzhou University
- Changzhou 213164
| | - Jin-Tao Yu
- School of Petrochemical Engineering
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Jiangsu Province Key Laboratory of Fine Petrochemical Engineering
- Changzhou University
- Changzhou 213164
| | - Jiang Cheng
- School of Petrochemical Engineering
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology
- Jiangsu Province Key Laboratory of Fine Petrochemical Engineering
- Changzhou University
- Changzhou 213164
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11
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Kawamoto T, Matsubara H, Ryu I. A Theoretical Study on Reduction of Acyl Radicals with Borohydride Anions. CHEM LETT 2014. [DOI: 10.1246/cl.140370] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Takuji Kawamoto
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University
| | - Hiroshi Matsubara
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University
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12
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13
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14
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Abstract
This review article focuses on state-of-the-art borohydride based radical reactions, also covering earlier work, kinetics and some DFT calculations with respect to the hydrogen transfer mechanism.
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Affiliation(s)
- Takuji Kawamoto
- Department of Chemistry
- Graduate School of Science
- Osaka Prefecture University
- Sakai, Japan
| | - Ilhyong Ryu
- Department of Chemistry
- Graduate School of Science
- Osaka Prefecture University
- Sakai, Japan
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15
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Zhao J, Li P, Xia C, Li F. Direct N-acylation of azoles via a metal-free catalyzed oxidative cross-coupling strategy. Chem Commun (Camb) 2014; 50:4751-4. [DOI: 10.1039/c4cc01587h] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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16
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Liu J, Liu Q, Yi H, Qin C, Bai R, Qi X, Lan Y, Lei A. Visible-Light-Mediated Decarboxylation/Oxidative Amidation of α-Keto Acids with Amines under Mild Reaction Conditions Using O2. Angew Chem Int Ed Engl 2013; 53:502-6. [DOI: 10.1002/anie.201308614] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Indexed: 11/07/2022]
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17
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Liu J, Liu Q, Yi H, Qin C, Bai R, Qi X, Lan Y, Lei A. Visible-Light-Mediated Decarboxylation/Oxidative Amidation of α-Keto Acids with Amines under Mild Reaction Conditions Using O2. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201308614] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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18
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Fukuyama T, Nakashima N, Okada T, Ryu I. Free-Radical-Mediated [2 + 2 + 1] Cycloaddition of Acetylenes, Amidines, and CO Leading to Five-Membered α,β-Unsaturated Lactams. J Am Chem Soc 2013; 135:1006-8. [DOI: 10.1021/ja312654q] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takahide Fukuyama
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531,
Japan
| | - Nao Nakashima
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531,
Japan
| | - Takuma Okada
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531,
Japan
| | - Ilhyong Ryu
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531,
Japan
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19
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Wille U. Radical Cascades Initiated by Intermolecular Radical Addition to Alkynes and Related Triple Bond Systems. Chem Rev 2012; 113:813-53. [DOI: 10.1021/cr100359d] [Citation(s) in RCA: 465] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Uta Wille
- School of Chemistry and
BIO21 Molecular Science and
Biotechnology Institute, Australian Research Council Centre of Excellence
for Free Radical Chemistry and Biotechnology, The University of Melbourne, 30 Flemington Road, Parkville, Victoria
3010, Australia
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20
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Park Y, Lee YJ, Hong S, Kim MH, Lee M, Kim TS, Lee JK, Jew SS, Park HG. Highly Enantioselective Phase-Transfer Catalytic α-Alkylation of α-tert-Butoxycarbonyllactams: Construction of β-Quaternary Chiral Pyrrolidine and Piperidine Systems. Adv Synth Catal 2011. [DOI: 10.1002/adsc.201100542] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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21
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Pandey G, Prasanna Kumara C, Kumar Burugu S, Puranik VG. Enantioselective Total Syntheses of (-)-Isonitramine, (-)-Sibirine, and (+)-Nitramine by Ring-Closing Metathesis. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101256] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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Breuning MA, Harms K, Koert U. The imidato-alkenyllithium route for the synthesis of the isoquinocycline-pyrrolopyrrole substructure. Org Lett 2011; 13:1402-5. [PMID: 21338054 DOI: 10.1021/ol200085g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A convergent and effective synthesis of the pyrrolopyrrole substructure (CDEFG) of the isoquinocyclines is reported. A key step is a tin-lithium exchange of an imidato-alkenyltin compound (a ring G equivalent) and the subsequent acylation with a lactone. The resulting acetal is used successfully for the ring F closure to the pyrrolopyrrole. The sole formation of the isoquinocycline N,O-acetal epimer is in accordance with the proposed mechanism for the isomerization of quinocyclines to isoquinocyclines.
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Affiliation(s)
- M André Breuning
- Fachbereich Chemie, Philipps-University Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany
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23
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Ryu I, Fukuyama T, Tojino M, Uenoyama Y, Yonamine Y, Terasoma N, Matsubara H. Radical carbonylation of ω-alkynylamines leading to α-methylene lactams. Synthetic scope and the mechanistic insights. Org Biomol Chem 2011; 9:3780-6. [DOI: 10.1039/c1ob05145h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yu JD, Ding W, Lian GY, Song KS, Zhang DW, Gao X, Yang D. Selective Approach toward Multifunctionalized Lactams by Lewis Acid Promoted PhSe Group Transfer Radical Cyclization. J Org Chem 2010; 75:3232-9. [DOI: 10.1021/jo100139u] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jin-Di Yu
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Wei Ding
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Gao-Yan Lian
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Ke-Sheng Song
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Dan-Wei Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Xiang Gao
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Dan Yang
- Department of Chemistry, Fudan University, Shanghai 200433, China
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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25
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Lamas MC, Vaillard SE, Wibbeling B, Studer A. Radical Amination with Trimethylstannylated Benzophenone Imine. Org Lett 2010; 12:2072-5. [DOI: 10.1021/ol1005455] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marie-Céline Lamas
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Santiago E. Vaillard
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Birgit Wibbeling
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
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26
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Ryu IH, Fukuyama T, Nobuta O, Uenoyama Y. Stannylcarbonylation of Hydroxy-substituted Alkynes. Intramoleuclar Trapping of α-Ketenyl Radicals by a Hydroxy Group Leading to Lactols. B KOREAN CHEM SOC 2010. [DOI: 10.5012/bkcs.2010.31.03.545] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Ryu I, Kobayashi S, Hirao H, Kawauchi T. Novel Radical Cyclization Method Accompanied by Elimination of Hydrazyl Radical. HETEROCYCLES 2010. [DOI: 10.3987/com-09-s(s)115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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28
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Tzirakis MD, Orfanopoulos M. Acyl radical reactions in fullerene chemistry: direct acylation of [60]fullerene through an efficient decatungstate-photomediated approach. J Am Chem Soc 2009; 131:4063-9. [PMID: 19292491 DOI: 10.1021/ja808658b] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A versatile and highly efficient photochemical methodology for the direct acylation of C(60) has been developed. This approach utilizes a wide variety of acyl radicals derived from aldehydes through a hydrogen atom abstraction process mediated by tetrabutylammonium decatungstate [(n-Bu(4)N)(4)W(10)O(32)]. The single addition reaction of these acyl radicals to [60]fullerene proceeded selectively to afford a novel class of previously unexplored fullerene-based materials. Product analysis of this reaction showed that decarbonylation and acylation pathways compete when a tertiary or phenylacetyl aldehyde is the starting material. However, a decrease of the reaction temperature was found to be effective in overcoming the decarbonylation encountered in certain acyl radical additions to C(60); the carbonyl radical addition precedes decarbonylation even in the cases where the decarbonylation rate constant exceeds 10(6) s(-1) (i.e., phenylacetaldehyde). The regiochemistry of the t-butyl radical addition was also found to be thermally controlled. The present methodology is directly applicable even in the cases of the cyclopropyl-substituted aldehydes, where rapid rearrangement of the cyclopropyl acyl radical intermediate can potentially occur. A mechanistic approach for this new reactivity of C(60) has been also provided, based mainly on intra- and intermolecular deuterium isotope effect studies.
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Affiliation(s)
- Manolis D Tzirakis
- Department of Chemistry, University of Crete, 71003 Voutes, Heraklion, Crete, Greece
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Abstract
All in one pot! Radical, radical-ionic, and radical-organometallic MCR are highly convergent processes, representing a useful pathway to molecular and structural diversity (see scheme). This concept article highlights recent developments in the field and shows the potential of the strategy for the economical elaboration of various kinds of organic substrates.Progress in multicomponent reactions (MCRs) based on ionic and organometallic processes has recently allowed the synthesis, with high efficiency, of large collections of drug-like molecules. In contrast, MCRs based on cascade radical reactions appear to have attracted, so far, much less interest. This concept article highlights the latest progress in the field and underlines the potential of such an approach. The collected examples demonstrate that radical and radical-ionic MCRs are highly convergent processes leading to useful structural diversity.
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Affiliation(s)
- Edouard Godineau
- University Bordeaux-1, Institut des Sciences Moléculaires, ISM-UMR 5255, 351, cours de la libération 33405 Talence Cedex, France
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Nöth J, Frankowski KJ, Neuenswander B, Aubé J, Reiser O. Efficient synthesis of gamma-lactams by a tandem reductive amination/lactamization sequence. JOURNAL OF COMBINATORIAL CHEMISTRY 2008; 10:456-9. [PMID: 18338857 PMCID: PMC2713763 DOI: 10.1021/cc700202c] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A three-component method for the synthesis of highly substituted gamma-lactams from readily available maleimides, aldehydes, and amines is described. A new reductive amination/intramolecular lactamization sequence provides a straightforward route to the lactam products in a single manipulation. The general utility of this method is demonstrated by the parallel synthesis of a gamma-lactam library.
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Affiliation(s)
- Julica Nöth
- Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
- Center for Chemical Methodology and Library Development, 1501 Wakarusa Drive, Lawrence, Kansas 66047
| | - Kevin J. Frankowski
- Center for Chemical Methodology and Library Development, 1501 Wakarusa Drive, Lawrence, Kansas 66047
| | - Benjamin Neuenswander
- Center for Chemical Methodology and Library Development, 1501 Wakarusa Drive, Lawrence, Kansas 66047
| | - Jeffrey Aubé
- Center for Chemical Methodology and Library Development, 1501 Wakarusa Drive, Lawrence, Kansas 66047
| | - Oliver Reiser
- Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
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Coeffard V, Thobie-Gautier C, Beaudet I, Le Grognec E, Quintard JP. Mild Electrochemical Deprotection ofN-PhenylsulfonylN-Substituted Amines Derived from (R)-Phenylglycinol. European J Org Chem 2008. [DOI: 10.1002/ejoc.200700709] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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