1
|
Kano T, Uozumi R, Maruyama T, Tada N, Itoh A. Modular Synthesis of Tripeptide Analogs with an Aminobitriazole Skeleton Using Diynyl Benziodoxolone as a Trivalent Platform. J Org Chem 2024; 89:11761-11765. [PMID: 39082689 DOI: 10.1021/acs.joc.4c00999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
A new synthesis method of tripeptide analogs with an aminobitriazole skeleton was proposed. The method involves assembling three amino acid-derived modules at the amino group site and onto a triisopropylsilyl diynyl benziodoxolone by copper-catalyzed electrophilic diynylation of amino acid-derived sulfonamides, chemoselective azide-alkyne cycloadditions with amino acid-derived azides, and deprotection. Various complex aminobitriazoles substituted with pyrene, nucleoside, and N-acetylglucosamine were also synthesized. The produced aminobitriazoles have three sp3 chiral centers and a C-N axial chirality.
Collapse
|
2
|
Yamaguchi E, Murai M, Itoh A. Halogen-Bonding-Enabled Photoinduced Atom Transfer Radical Addition/Cyclization Reaction Leading to Tricyclic Heterocycles. J Org Chem 2024; 89:6555-6563. [PMID: 38657225 DOI: 10.1021/acs.joc.4c00204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Atom transfer radical addition (ATRA) reactions are crucial for the dual functionalization of unsaturated hydrocarbons. Radical generation, pivotal in ATRA, has seen advancements from thermal to photochemical methods. Recent focus on halogen-bonding-based radical generation, including our group's innovative photochemical approach, offers cost-effective alternatives to transition-metal-dependent photocatalysts. This eliminates the need for high-energy UV light, enhancing the efficiency with noncovalent interactions.
Collapse
|
3
|
Matsuo K, Yamaguchi E, Itoh A. Halogen-Bonding-Promoted Photoinduced C-X Borylation of Aryl Halide Using Phenol Derivatives. J Org Chem 2023; 88:6176-6181. [PMID: 37083371 DOI: 10.1021/acs.joc.3c00201] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
This study investigates the photoinduced C-X borylation reaction of aryl halides by forming a halogen-bonding (XB) complex using 2-naphthol as an XB acceptor. The method is chemoselective and broadly functional group tolerant and provides concise access to corresponding boronate esters. Mechanistic studies reveal that forming the XB complex between aryl halide and naphthol acts as an electron donor-acceptor complex to furnish aryl radicals through photoinduced electron transfer.
Collapse
|
4
|
Stehlik J, Schroder J, Pinney S, Patel C, D'Alessandro D, Goldstein D, Jorde U, Patel S, Mani D, Esmailian F, Kobashigawa J, Takeda K, Uriel N, Pham S, Patel P, Kai M, Sun B, Shah A, Ono M, Couper G, DeNofrio D, Vest A, Joyce D, DeVore A, Mallidi H, Itoh A, Mehra M, Givertz M, Milano C, Farr M. First Report of the Transmedics Organ Care System Heart Perfusion Registry. A Multi-Institutional Outcomes Analysis. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
|
5
|
Milano C, Schroder J, Farr M, DeVore A, D'Alessandro D, Goldstein D, Jorde U, Patel S, Daneshmand M, Pinney S, Esmailian F, Kobashigawa J, Takeda K, Uriel N, Pham S, Patel P, Kai M, Sun B, Shah A, Ono M, Couper G, DeNofrio D, Vest A, Joyce D, Mallidi H, Itoh A, Mehra M, Givertz M, Patel C, Stehlik J. Demographics and Outcomes of Clinical Trial vs Initial Post-Approval Use of Transmedics Organ Care System Heart. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
|
6
|
Maejima S, Yamaguchi E, Itoh A. Visible-Light-Induced Regioselective Functionalization of α-Olefin: Development of One-Pot Photo-Synthesis of C 3-Substituted Dihydrobenzofurans. Org Lett 2023; 25:1856-1861. [PMID: 36866934 DOI: 10.1021/acs.orglett.3c00335] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
A method for the catalytic regioselective synthesis of C3-substituted dihydrobenzofurans (DHBs) via [2 + 2] photocycloaddition of alkene and p-benzoquinone is developed. This method realizes the rapid synthesis of DHBs with readily available substrates and simple reaction conditions by using Lewis acid B(C6F5)3 and Lewis base P(o-tol)3 as a catalyst in combination with the classical Paternò-Büchi reaction.
Collapse
|
7
|
Nakashima KI, Okamura M, Matsumoto I, Kameda N, Tsuboi T, Yamaguchi E, Itoh A, Inoue M. Regulation of adipogenesis through retinoid X receptor and/or peroxisome proliferator-activated receptor by designed lignans based on natural products in 3T3-L1 cells. J Nat Med 2023; 77:315-326. [PMID: 36607539 DOI: 10.1007/s11418-022-01674-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/22/2022] [Indexed: 01/07/2023]
Abstract
We previously synthesized two retinoid X receptor (RXR) agonists, 4'-hydroxy-3'-propyl-[1,1'-biphenyl]-3-propanoic acid ethyl ester (4'OHE) and 6-hydroxy-3'-propyl-[1,1'-biphenyl]-3-propanoic acid ethyl ester (6OHE), based on the structure of magnaldehyde B, a natural product obtained from Magnolia obovata. 4'OHE and 6OHE exhibited different selectivities for peroxisome proliferator-activated receptor (PPAR)/RXR heterodimers. To examine the regulatory effects of these compounds in adipogenesis, 3T3-L1 mouse preadipocytes were treated with a differentiation cocktail with or without test compounds to induce differentiation, and subsequently treated with test compounds in insulin-containing medium every alternate day. Lipid droplets were stained with Oil Red O to examine lipid accumulation. In addition, adipogenesis-related gene expression was measured using RT-qPCR and immunoblotting. The results showed that a PPARγ agonist, 4'OHE, which exerts agonistic effects on PPARγ and RXRα, enhanced adipogenesis similar to rosiglitazone. However, unlike GW501516, a PPARδ agonist, 6OHE and its hydrolysis product (6OHA), which exert agonistic effects on PPARδ and RXRα, suppressed adipogenesis. In a manner similar to 6OHE and 6OHA, bexarotene, an RXR agonist, suppressed adipocyte differentiation, and its anti-adipogenic effect was reversed by an RXR antagonist. Furthermore, 6OHA and bexarotene inhibited the increase in Pparγ2 and Cebpa mRNA levels 2 days after the induction of differentiation. We demonstrated the adipogenic effect of 4'OHE and anti-adipogenic effects of 6OHE and 6OHA in 3T3-L1 cells. Previously, RXR agonists have been reported to positively regulate the differentiation of mesenchymal stem cells into adipocytes, but our current data showed that they inhibited the differentiation of preadipocytes, at least 3T3-L1 cells, into adipocytes.
Collapse
|
8
|
Kawakami R, Usui S, Tada N, Itoh A. Late-stage diversification strategy for synthesizing ynamides through copper-catalyzed diynylation and azide-alkyne cycloaddition. Chem Commun (Camb) 2023; 59:450-453. [PMID: 36519388 DOI: 10.1039/d2cc05575a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A late-stage diversification strategy for synthesizing ynamides has been developed. This strategy was enabled by the copper-catalyzed direct electrophilic diynylation of sulfonamides with a novel triisopropylsilyl diynyl benziodoxolone, deprotection, and the late-stage chemoselective copper-catalyzed azide-alkyne cycloaddition sequence, which yields various complex molecule-derived ynamides with pyrene, amino acid, nucleoside, and N-acetylglucosamine as substituents.
Collapse
|
9
|
Itoh A, Tanemura T, Tada N, Yamaguchi E. Development of a fully automated continuous, integrated production system for all reaction processes of ibuprofen. REACT CHEM ENG 2023. [DOI: 10.1039/d3re00045a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
We developed a continuous, integrated production system for all reaction processes targeting ibuprofen. We succeeded in obtaining pure ibuprofen at 38% for all steps, and a production efficiency of 47...
Collapse
|
10
|
Shimizu A, Shibata A, Kano T, Kumai Y, Kawakami R, Esaki H, Fukushima K, Tada N, Itoh A. Synthesis of 4-Imidazolidinones from Diamides and Ethynyl Benziodoxolones via Double Michael-Type Addition: Ethynyl Benziodoxolones as Electrophilic Ynol Synthons. Org Lett 2022; 24:8859-8863. [DOI: 10.1021/acs.orglett.2c03648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
11
|
Kudo Y, Endo S, Tanio M, Saka T, Himura R, Abe N, Takeda M, Yamaguchi E, Yoshino Y, Arai Y, Kashiwagi H, Oyama M, Itoh A, Shiota M, Fujimoto N, Ikari A. Antiandrogenic Effects of a Polyphenol in Carex kobomugi through Inhibition of Androgen Synthetic Pathway and Downregulation of Androgen Receptor in Prostate Cancer Cell Lines. Int J Mol Sci 2022; 23:ijms232214356. [PMID: 36430833 PMCID: PMC9696374 DOI: 10.3390/ijms232214356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
Prostate cancer (PC) represents the most common cancer disease in men. Since high levels of androgens increase the risk of PC, androgen deprivation therapy is the primary treatment; however this leads to castration-resistant PC (CRPC) with a poor prognosis. The progression to CRPC involves ectopic androgen production in the adrenal glands and abnormal activation of androgen signaling due to mutations and/or amplification of the androgen receptor (AR) as well as activation of androgen-independent proliferative pathways. Recent studies have shown that adrenal-derived 11-oxygenated androgens (11-ketotestosterone and 11-ketodihydrotestosterone) with potencies equivalent to those of traditional androgens (testosterone and dihydrotestosterone) are biomarkers of CRPC. Additionally, dehydrogenase/reductase SDR family member 11 (DHRS11) has been reported to be a 17β-hydroxysteroid dehydrogenase that catalyzes the production of the 11-oxygenated and traditional androgens. This study was conducted to evaluate the pathophysiological roles of DHRS11 in PC using three LNCaP, C4-2 and 22Rv1 cell lines. DHRS11 silencing and inhibition resulted in suppression of the androgen-induced expression of AR downstream genes and decreases in the expression of nuclear AR and the proliferation marker Ki67, suggesting that DHRS11 is involved in androgen-dependent PC cell proliferation. We found that 5,7-dihydroxy-8-methyl-2-[2-(4-hydroxyphenyl)ethenyl]-4H-1-benzopyran-4-one (Kobochromone A, KC-A), an ingredient in the flowers of Carex kobomugi, is a novel potent DHRS11 inhibitor (IC50 = 0.35 μM). Additionally, KC-A itself decreased the AR expression in PC cells. Therefore, KC-A suppresses the androgen signaling in PC cells through both DHRS11 inhibition and AR downregulation. Furthermore, KC-A enhanced the anticancer activity of abiraterone, a CRPC drug, suggesting that it may be a potential candidate for the development of drugs for the prevention and treatment of CRPC.
Collapse
|
12
|
Okazaki K, Takeda M, Yamaguch E, Heishima K, Itoh A. Rapid Total Synthesis of Petasin and Isopetasin. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.154092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
13
|
Bakir N, Florea I, Damiano M, Schilling J, Hartupee J, Ewald G, Kotkar K, Itoh A, Masood M. Longitudinal Risk Factors for Driveline Infection in Destination Therapy Patients with Left Ventricular Assist Device Support. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.1474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
14
|
Yamaguchi E, Abe A, Itoh A. Synthesis of Dibenzo[g,p]Chrysenes via Organophotocatalytic Sequential Single‐Electron Oxidation. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202200039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
15
|
Yamaguchi E, Inagawa H, Itoh A. Selenonium ylides: synthesis, characterization, and applications to photo-induced cyclopropanation reactions. Photochem Photobiol Sci 2022; 21:813-818. [PMID: 35048305 DOI: 10.1007/s43630-021-00155-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/01/2021] [Indexed: 11/26/2022]
Abstract
Carbenes are important and highly reactive intermediates for the synthesis of various complex molecules. They are now an indispensable chemical species in organic chemistry and are used frequently to synthesize complex compounds in drug discovery chemistry. In general, carbenes are synthesized by a combination of transition metal catalysts and diazo compounds or by the decomposition reactions of diazo compounds. This paper reports the development of the visible light for the photochemical generation of carbenes from a novel C,Se-selenonium ylide. Overall, this photochemical carbene generation method using C,Se-selenonium ylide does not require a catalyst, is simple to perform, and enables highly efficient cyclopropanation reactions with alkenes.
Collapse
|
16
|
Matsuo K, Yoshitake T, Yamaguchi E, Itoh A. Photoinduced Atom Transfer Radical Addition/Cyclization Reaction between Alkynes or Alkenes with Unsaturated α-Halogenated Carbonyls. Molecules 2021; 26:molecules26226781. [PMID: 34833874 PMCID: PMC8618827 DOI: 10.3390/molecules26226781] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/03/2021] [Accepted: 11/07/2021] [Indexed: 11/16/2022] Open
Abstract
We have developed a photochemical ATRA/ATRC reaction that is mediated by halogen bonding interactions. This reaction is caused by the reaction of malonic acid ester derivatives containing bromine or iodine with unsaturated compounds such as alkenes and alkynes in the presence of diisopropylethylamine under visible light irradiation. As a result of various control experiments, it was found that the formation of complexes between amines and halogens by halogen-bonding interaction occurs in the reaction system, followed by the cleavage of the carbon-halogen bonds by visible light, resulting in the formation of carbon radicals. In this reaction, a variety of substrates can be used, and the products, cyclopentenes and cyclopentanes, were obtained by intermolecular addition and intramolecular cyclization.
Collapse
|
17
|
Matsuo K, Kondo T, Yamaguchi E, Itoh A. Photoinduced Atom Transfer Radical Addition Reaction of Olefins with α-Bromo Carbonyls. Chem Pharm Bull (Tokyo) 2021; 69:796-801. [PMID: 34334524 DOI: 10.1248/cpb.c21-00360] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The irradiation of halogen-bonded complexes with light leads to the homolysis of carbon-halogen bonds and the formation of the corresponding carbon radical species. However, the only methodology reported for these halogen-bonding complexes is using CBr4 as the halogen-bond donor and its applicability is of great interest. In this study, the atom transfer radical addition (ATRA) reaction of olefins using bromomalonates as halogen-bonding donors was developed. Using 4-phenylpyridine as the halogen-bonding acceptor, the desired reaction proceeded well under external irradiation of 380 nm light to furnish the corresponding ATRA reaction product. The ATRA reaction was effective in generating the corresponding products for a variety of olefins. Furthermore, the ATRA reaction was applicable to bulky ketones, substrates, and malonate esters. The intermediates of the reaction were identified and a plausible reaction mechanism was proposed.
Collapse
|
18
|
Takeda M, Maejima S, Yamaguchi E, Itoh A. Iodine-mediated direct α-amination of dimethyl methylmalonate using non-protected amines. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Ikeda I, Itoh A, Kuo PL, Okahara M. Structural Effects of the Isomeric Hydrophilic Groups of Surfactants on their Properties. TENSIDE SURFACT DET 2021. [DOI: 10.1515/tsd-1984-210510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
20
|
Yamaguchi E, Itoh A, Suzuki H. Nickel-Catalyzed Reductive Allylation of Aldehydes with Allyl Acetates. SYNTHESIS-STUTTGART 2021. [DOI: 10.1055/s-0040-1705961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractCarbonyl allylation reactions constitute an important step in the formation of carbon–carbon reactions, and involve various related reactions that chiefly use allylmetal reagents. This report presents a nickel-catalyzed carbonyl allylation reaction using allyl acetate, which produces homoallyl alcohols in moderate to good yields, as an efficient methodology under reductive coupling conditions.
Collapse
|
21
|
Shimbo D, Maruyama T, Tada N, Itoh A. N-Alkenylation of hydroxamic acid derivatives with ethynyl benziodoxolone to synthesize cis-enamides through vinyl benziodoxolones. Org Biomol Chem 2021; 19:2442-2447. [PMID: 33666207 DOI: 10.1039/d1ob00055a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The stereoselective synthesis of cis-β-N-alkoxyamidevinyl benziodoxolones (cis-β-N-RO-amide-VBXs) from O-alkyl hydroxamic acids in the presence of an ethynyl benziodoxolone-acetonitrile complex (EBX-MeCN) is reported herein. The reaction was performed under mild conditions including an aqueous solvent, a mild base, and room temperature. The reaction tolerated various O-alkyl hydroxamic acids derived from carboxylic acids, such as amino acids, pharmaceuticals, and natural products. Vinyl dideuterated cis-β-N-MeO-amide-VBXs were also synthesized using deuterium oxide as the deuterium source. Valine-derived cis-β-N-MeO-amide-VBX was stereospecifically derivatized to hydroxamic acid-derived cis-enamides without the loss of stereoselectivity or reduction in the deuterium/hydrogen ratio.
Collapse
|
22
|
Takai R, Shimbo D, Tada N, Itoh A. Ligand-Enabled Copper-Catalyzed N-Alkynylation of Sulfonamide with Alkynyl Benziodoxolone: Synthesis of Amino Acid-Derived Ynamide. J Org Chem 2021; 86:4699-4713. [PMID: 33719425 DOI: 10.1021/acs.joc.1c00101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ynamides are versatile building blocks in organic synthesis. However, the synthesis of amino acid-derived ynamides is difficult but in high demand. Herein, we disclose the copper-catalyzed Csp-N coupling of sulfonamide, including amino acid and peptide derivatives, to give ynamides by using alkynyl benziodoxolones with broad functional group tolerance under mild reaction conditions. The electron-rich bipyridine as a ligand and ethanol as solvent were used for the success of this reaction. The usefulness of the obtained amino acid-derived ynamide as building block was showcased by further derivatization to unique amino acid derivatives. A control experiment to elucidate the mechanistic insight was also described.
Collapse
|
23
|
Ura T, Shimbo D, Yudasaka M, Tada N, Itoh A. Synthesis of Phenol-Derived cis-Vinyl Ethers Using Ethynyl Benziodoxolone. Chem Asian J 2020; 15:4000-4004. [PMID: 33058543 DOI: 10.1002/asia.202001102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/07/2020] [Indexed: 12/19/2022]
Abstract
The stereoselective synthesis of cis-β-phenoxyvinyl benziodoxolones (cis-β-phenol-VBXs) from an ethynyl benziodoxolone-acetonitrile complex (EBX-MeCN) and various phenols is reported herein. The reaction tolerates different phenol derivatives, including complex natural products, and can be conducted under mild conditions. The synthesis was performed in an aqueous solvent in the absence and presence of a catalytic amount of a base. Selectively mono- and di-deuterated cis-β-phenol-VBXs were also prepared. cis-β-Phenol-VBXs were stereospecifically derivatized to cis-alkynylvinyl ethers and cis-iodovinyl ethers without loss of stereoselectivity or reduction in the deuterium/hydrogen ratio.
Collapse
|
24
|
Maejima S, Yamaguchi E, Itoh A. Three-Component Iminolactonization Reaction via Bifunctionalization of Olefins Using Molecular Iodine and Visible Light. J Org Chem 2020; 85:10709-10718. [PMID: 32806099 DOI: 10.1021/acs.joc.0c01251] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel three-component γ-iminolactonization reaction was developed, which relied on the C-C/C-O bond-forming bifunctionalization of olefins using molecular iodine and visible light. This strategy did not require any (heavy) metal reagents for double-bond activation because molecular iodine acted as a rare-metal-alternative reagent through visible light irradiation. In addition, the preactivation of amines and other substrates is not required. The mechanistic investigation revealed that the generated iodine radicals under visible light irradiation reacted with alkenes to form a highly reactive intermediate; then, the three-component reaction of diiodide, malonate, and amine furnished iminolactone. Of note, the developed reaction is simple and realized the diversity-oriented synthesis innovative methodology of γ-iminolactone derivatives in drug discovery chemistry.
Collapse
|
25
|
Matsuo K, Yamaguchi E, Itoh A. In Situ-Generated Halogen-Bonding Complex Enables Atom Transfer Radical Addition (ATRA) Reactions of Olefins. J Org Chem 2020; 85:10574-10583. [DOI: 10.1021/acs.joc.0c01135] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|