1
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Patil VB, Raghu Ramudu G, Chegondi R. Cascade Oxypalladation/1,3-Palladium Shift to Access Cyclopentene-Fused Isocoumarins. Org Lett 2024; 26:6353-6358. [PMID: 39041835 DOI: 10.1021/acs.orglett.4c01997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Fused isocoumarins are frequently found in several natural products and pharmaceuticals. Herein, a cascade annulation of 2-alkynylbenzoate-tethered cyclic 1,3-diones via sequential trans-oxypalladation, carbonyl insertion, 1,3-Pd shift, and β-hydride elimination is reported. This method provides efficient access to highly diastereoselective tetracyclic cyclopentene-fused isocoumarins containing two contiguous quaternary stereocenters. A plausible reaction mechanism is proposed on the basis of mechanistic studies, including deuterium labeling experiments. Studies toward enantioselective synthesis using a chiral Bpy ligand gave encouraging initial results.
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Affiliation(s)
- Vaibhav B Patil
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - G Raghu Ramudu
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rambabu Chegondi
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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2
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Kattula B, Munakala A, Kashyap R, Nallamilli T, Nagendla NK, Naza S, Mudiam MKR, Chegondi R, Addlagatta A. Strategic enzymatic enantioselective desymmetrization of prochiral cyclohexa-2,5-dienones. Chem Commun (Camb) 2024; 60:6647-6650. [PMID: 38856301 DOI: 10.1039/d4cc02181a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Asymmetric desymmetrization through the selective reduction of one double bond of prochiral 2,5-cyclohexadienones is highly challenging. A novel method has been developed for synthesizing chiral cyclohexenones by employing an ene-reductase (Bacillus subtilis YqjM) enzyme that belongs to the OYE family. Our strategy demonstrates high substrate scope and enantioselectivity towards substrates containing all-carbon as well as heteroatom (O, N)-containing quaternary centers. The mechanistic studies (kH/D = ∼1.8) indicate that hydride transfer is probably the rate-limiting step. Mutation of several active site residues did not affect the stereochemical outcomes. This work provides a convenient way of synthesizing various enantioselective γ,γ-disubstituted cyclohexanones using enzymes.
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Affiliation(s)
- Bhavita Kattula
- Department of Applied Biology, Hyderabad, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Anandarao Munakala
- Department of Organic Synthesis and Process Chemistry, Hyderabad, Telangana, India.
| | | | - Tarun Nallamilli
- Department of Organic Synthesis and Process Chemistry, Hyderabad, Telangana, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Narendra Kumar Nagendla
- Department of Analytical and Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, Telangana, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Surabhi Naza
- Department of Applied Biology, Hyderabad, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Mohana Krishna Reddy Mudiam
- Department of Analytical and Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, Telangana, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Rambabu Chegondi
- Department of Organic Synthesis and Process Chemistry, Hyderabad, Telangana, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Anthony Addlagatta
- Department of Applied Biology, Hyderabad, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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3
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Magham LR, Samad A, Thopate SB, Nanubolu JB, Chegondi R. Organocatalytic enantioselective desymmetrization of enal-tethered cyclohexane-1,3-diones. Chem Commun (Camb) 2024; 60:3834-3837. [PMID: 38497248 DOI: 10.1039/d4cc00487f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Organocatalytic asymmetric desymmetrization of prochiral cyclohexane-1,3-diones has been demonstrated through the merging of iminium and enamine activation. The tandem annulation reaction proceeds through a sequential oxa-Michael addition/intramolecular aldol reaction/[1,3]-amino oxetane rearrangement pathway. Mechanistic study using an 18O-water experiment suggests oxetane rearrangement instead of direct dehydration. The formation of other competing Rauhut-Currier products via alkoxy-elimination was not observed.
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Affiliation(s)
- Lakshmi Revati Magham
- Department of Organic Synthesis and Process Chemistry, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Abdus Samad
- Department of Organic Synthesis and Process Chemistry, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Satish B Thopate
- Department of Organic Synthesis and Process Chemistry, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jagadeesh Babu Nanubolu
- Department of Analytical and Structural chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rambabu Chegondi
- Department of Organic Synthesis and Process Chemistry, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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4
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Li Z, Zhang Y, Sun M, Zhang Y, Lu Z, Deng Y, Huang X, Shen G. La(OTf) 3-Catalyzed [3+2] Cycloaddition Reactions for the Synthesis of Benzo[ d]oxazoles/Benzofurans. J Org Chem 2024; 89:3809-3820. [PMID: 38395778 DOI: 10.1021/acs.joc.3c02641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
The La(OTf)3-catalyzed [3+2] cycloaddition reactions for the synthesis of benzo[d]oxazoles/benzofurans via quinones and 1,2-di-tert-butyl-3-(cyanimino)diaziridine (1,3-di-tert-butyl-2-cyanoguanidine)/vinyl azides have been explored. A series of 5-hydroxybenzofuran-4-carboxylic acid derivatives and 5-hydroxybenzo[d]oxazole-4-carboxylic acid derivatives were conveniently obtained with high yields and good stereoselectivities, which could be used for further transformations to valuable compounds.
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Affiliation(s)
- Zhanjun Li
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
- Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Road, Dalian 116024, P. R. China
| | - Yalin Zhang
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
| | - Manman Sun
- Advanced Research Institute and School of Pharmaceutical Sciences, Taizhou University, Jiaojiang, Zhejiang 318000, P. R. China
| | - Ye Zhang
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
| | - Zhaoxiang Lu
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
| | - Yupeng Deng
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
| | - Xianqiang Huang
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
| | - Guodong Shen
- School of Chemistry and Chemical Engineering, Liaocheng University, 1 Hunan Avenue, Liaocheng 252000, Shandong, P. R. China
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5
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Magham LR, Thopate SB, Samad A, Chegondi R. Enantioselective Desymmetrization Triggered by Iminium-Enamine Activation: Access to Complex Cyclohepta[b]indoles. Chemistry 2023; 29:e202203435. [PMID: 36530064 DOI: 10.1002/chem.202203435] [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: 11/04/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
The expeditious construction of complex molecules having multiple stereocentres is highly desirable in organic chemistry. In the present communication, we report the development of an organocatalytic asymmetric desymmetrization of prochiral enal-tethered cyclohexadienones via the C3-selective Friedel-Crafts alkylation of indoles triggered by LUMO-lowering iminium activation/HOMO-raising enamine activation. The reaction provides access to bicyclic enones, which further undergo acid-mediated intramolecular annulation from C2-position to afford highly strained cyclohepta[b]indoles with five contiguous stereocentres and three new C-C bonds in excellent enantioselectivity and diastereoselectivity.
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Affiliation(s)
- Lakshmi Revati Magham
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India
| | - Satish B Thopate
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India
| | - Abdus Samad
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India
| | - Rambabu Chegondi
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India
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6
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Donthoju A, Munakala A, Ellandula S, Chegondi R. Palladium(0)-Catalyzed Remote Decarboxylative Allylation and Base-Mediated 1,3-Migration. J Org Chem 2022; 87:8267-8276. [PMID: 35671458 DOI: 10.1021/acs.joc.2c00961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein we have reported the palladium(0)-catalyzed decarboxylative oxa-Michael addition/remote α-allylation/1,3- migration of prochiral allyl carbonate-tethered cyclohexadienones in good yields. This unconventional intramolecular rearrangement is triggered by the base-mediated retro-Michael ring-opening reaction (β-elimination) and subsequent syn-selective oxa-Michael addition on the less substituted enone functionality. The generality of tandem decarboxylative allylation was examined with various substrates and in the gram-scale reaction.
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Affiliation(s)
- Ashok Donthoju
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Anandarao Munakala
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sushma Ellandula
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India
| | - Rambabu Chegondi
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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7
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Jadhav SB, Dash SR, Maurya S, Nanubolu JB, Vanka K, Chegondi R. Enantioselective Cu(I)-catalyzed borylative cyclization of enone-tethered cyclohexadienones and mechanistic insights. Nat Commun 2022; 13:854. [PMID: 35165287 PMCID: PMC8844005 DOI: 10.1038/s41467-022-28288-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/06/2022] [Indexed: 12/12/2022] Open
Abstract
The catalytic asymmetric borylation of conjugated carbonyls followed by stereoselective intramolecular cascade cyclizations with in situ generated chiral enolates are extremely rare. Herein, we report the enantioselective Cu(I)-catalyzed β-borylation/Michael addition on prochiral enone-tethered 2,5-cyclohexadienones. This asymmetric desymmetrization strategy has a broad range of substrate scope to generate densely functionalized bicyclic enones bearing four contiguous stereocenters with excellent yield, enantioselectivity, and diastereoselectivity. One-pot borylation/cyclization/oxidation via the sequential addition of sodium perborate reagent affords the corresponding alcohols without affecting yield and enantioselectivity. The synthetic potential of this reaction is explored through gram-scale reactions and further chemoselective transformations on products. DFT calculations explain the requirement of the base in an equimolar ratio in the reaction, as it leads to the formation of a lithium-enolate complex to undergo C-C bond formation via a chair-like transition state, with a barrier that is 22.5 kcal/mol more favourable than that of the copper-enolate complex. Rapidly building molecular structures with both elements of complexity and flexibility is a key goal of organic synthesis. Here the authors show a tandem copper-catalyzed β-borylation/Michael addition on prochiral enone-tethered 2,5-cyclohexadienones, to generate bicyclic borylated products in high yield and enantioselectivity.
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8
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Chen J, Hu R, Bao Q, Shang D, Yu L, Chan PWH, Rao W. Ligand-controlled chemoselectivity in gold-catalyzed cascade cyclization of 1,4-diene-tethered 2-alkynylbenzaldehydes. Org Chem Front 2022. [DOI: 10.1039/d2qo01346k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A synthetic method that relies on the gold(i)-catalyzed cascade annulation of skipped 1,4-diene-tethered 2-alkynylbenzaldehydes for the chemo- and stereoselective assembly polycyclic bridged-pyrrolidines and -azepines is described.
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Affiliation(s)
- Jichao Chen
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Rui Hu
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Qing Bao
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Dandan Shang
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Lei Yu
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | | | - Weidong Rao
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
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9
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Hu R, Chen J, Wang Z, Shang D, Yu L, Chan PWH, Rao W. THF-Enabled PtBr 2-Catalyzed Desymmetric Hydrogenative [3 + 2] Cycloaddition of 2-Alkynylbenzaldehyde-Tethered Cyclohexadienones. Org Chem Front 2022. [DOI: 10.1039/d2qo00593j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A THF-enabled PtBr2-catalyzed desymmetric hydrogenative [3 + 2] cycloaddition of 2-alkynylbenzaldehyde-tethered cyclohexadienones has been developed. The protocol provides a highly functionalized 6-7-6 polycyclic skeleton with four contiguous stereocenters in good...
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10
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Jadhav SB, Maurya S, Navaneetha N, Chegondi R. Rh(III)-catalyzed diastereoselective cascade annulation of enone-tethered cyclohexadienones via C(sp 2)-H bond activation. Chem Commun (Camb) 2021; 57:13598-13601. [PMID: 34853840 DOI: 10.1039/d1cc05941f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we report highly diastereoselective arylative cyclization of enone-tethered cyclohexadienones via Rh(III)-catalyzed C-H activation of N-methoxybenzamides. This reaction proceeds through the formation of a five-membered rhodacycle followed by bis-Michael cascade annulation to access functionalized bicyclic scaffolds with four contiguous stereocenters with a broad substrate scope. These products have excellent functional handles, allowing further synthetic transformation to increase the structural complexity. Furthermore, mechanistic studies of arylative cyclization and a gram-scale experiment are also presented.
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Affiliation(s)
- Sandip B Jadhav
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sundaram Maurya
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - N Navaneetha
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rambabu Chegondi
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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11
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Nagireddy A, Dattatri, Babu Nanubolu J, Sridhar Reddy M. Diastereoselective [2+2+1] Hydrative Annulation of Phenol-Linked 1,6-Enynes with Acetylenes Through Rhodium Catalysis: A Rapid Access to Cyclopenta[b]benzofuranols. Chemistry 2021; 27:17570-17575. [PMID: 34636111 DOI: 10.1002/chem.202102930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Indexed: 12/18/2022]
Abstract
An unprecedented [2+2+1] hydrative annulation of 1,6-enynes with terminal alkynes is achieved using catalytic cationic Rh(I). Thus, a modular assembly of cyclopenta[b]benzofuranols with two consecutive quarternary stereocenters is achieved from readily available alkynes. The reaction is proposed to go through a sequence of 5-membered rhoda-cycle formation, regioselective acetylene insertion, 1,5 H-shift, substrate controlled stereoselective addition of water molecule followed by 1,2-rhodium migration gave contracted rhoda-cycle D and reductive elimination. Necessary control/labelling experiments were conducted to gain insight in to the mechanism.
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Affiliation(s)
- Attunuri Nagireddy
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500007, India.,Academy of Scientific and Innovative Research, Ghaziabad, 201002, India
| | - Dattatri
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500007, India.,Academy of Scientific and Innovative Research, Ghaziabad, 201002, India
| | - Jagadeesh Babu Nanubolu
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500007, India.,Analytical Department, CSIR-IICT, Hyderabad, 500007, India
| | - Maddi Sridhar Reddy
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500007, India.,Academy of Scientific and Innovative Research, Ghaziabad, 201002, India
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12
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Munakala A, Phanindrudu M, Chegondi R. Transition-Metal Catalyzed Stereoselective Desymmetrization of Prochiral Cyclohexadienones. CHEM REC 2021; 21:3689-3726. [PMID: 34145713 DOI: 10.1002/tcr.202100136] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 12/12/2022]
Abstract
The development of transition-metal catalyzed enantioselective and diastereoselective transformations has contributed many advances in the field of synthetic organic chemistry. Particularly, stereoselective desymmetrization of prochiral cyclohexadienones represents a powerful strategy for accessing highly functionalized and stereochemically enriched scaffolds, which are often found in biologically active compounds and natural products. In recent years, several research groups including our group have made a significant progress on transition-metal catalyzed stereoselective desymmetrizations of 2,5-cyclohexadienones. In this account, we will provide an overview of the recent developments in this area employing Pd, Cu, Rh, Au, Ag, Ni, Co, and Mn-catalysts.
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Affiliation(s)
- Anandarao Munakala
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Mandalaparthi Phanindrudu
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India
| | - Rambabu Chegondi
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500007, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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13
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Patil VB, Nanubolu JB, Chegondi R. Design, synthesis and application of spiro[4.5]cyclohexadienones via one-pot sequential p-hydroxybenzylation/oxidative dearomatization. Chem Commun (Camb) 2021; 57:5574-5577. [PMID: 33969843 DOI: 10.1039/d1cc01752g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One-pot sequential p-hydroxybenzylation/oxidative dearomatization/spiroannulation has been designed for the efficient construction of tetrahydrofuran containing spiro-cyclohexadienones. This reaction proceeds through the p-hydroxybenzylation of 1,3-diketones with p-hydroxybenzyl alcohol via quinone methide formation followed by oxidative dearomatization/spiroannulation with suitable alcohols. The Friedel-Crafts alkylation of spiro[4.5]cyclohexadienones with indoles provided a broad array of highly diastereoselective C-3 alkylated spirocycles and cyclohepta[b]indoles depending upon the ring size of the fused cyclic ketones.
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Affiliation(s)
- Vaibhav B Patil
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India. / and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jagadeesh Babu Nanubolu
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India and Department of Analytical and Structural chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India
| | - Rambabu Chegondi
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India. / and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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