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Atkin L, Ross HJ, Priebbenow DL. Acylsilanes in Transition-Metal-Catalyzed and Photochemical Reactions: Clarifying Product Formation. J Org Chem 2023; 88:14205-14209. [PMID: 37738455 DOI: 10.1021/acs.joc.3c01454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Acylsilanes are able to react as nucleophilic carbene precursors, electrophiles, and directing groups in C-H functionalization. To date, some of the products reportedly formed during transition-metal-catalyzed and photochemical reactions involving acylsilanes have been incorrectly assigned. To provide clarity, we herein address these structural misassignments and detail the revised structures. New insights into the reactivity of acylsilanes were also afforded via the discovery that light-induced siloxy carbenes participate in intramolecular 1,2-carbonyl addition to proximal esters.
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Affiliation(s)
- Liselle Atkin
- Department of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Hannah J Ross
- Department of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Daniel L Priebbenow
- Department of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
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Atkin L, Priebbenow D. The Indenyl Effect: Accelerated C‐H Amidation of Arenes via Ind*Rh(III) Nitrene Transfer Catalysis. Angew Chem Int Ed Engl 2023. [DOI: 10.1002/ange.202302175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Affiliation(s)
- Liselle Atkin
- Monash University MIPS: Monash Institute of Pharmaceutical Sciences Department of Medicinal Chemistry AUSTRALIA
| | - Daniel Priebbenow
- Monash University MIPS: Monash Institute of Pharmaceutical Sciences Medicinal Chemistry 381 Royal Pde 3052 Parkville AUSTRALIA
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Atkin L, Priebbenow D. The Indenyl Effect: Accelerated C-H Amidation of Arenes via Ind*Rh(III) Nitrene Transfer Catalysis. Angew Chem Int Ed Engl 2023; 62:e202302175. [PMID: 37019839 DOI: 10.1002/anie.202302175] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/27/2023] [Accepted: 04/05/2023] [Indexed: 04/07/2023]
Abstract
Investigations into C-H amidation reactions catalysed by cationic half-sandwich d6 metal complexes revealed that the indenyl-derived catalyst [Ind*RhCl2]2 significantly accelerated the directed ortho C-H amidation of benzoyl silanes using 1,4,2-dioxazol-5-ones. Ring slippage involving a haptotropic η5 to η3 rearrangement of the indenyl complex proposedly enables ligand substitution at the metal centre to proceed via associative, rather than dissociative pathways, leading to significant rate and yield enhancements. Intriguingly, this phenomenon appears specific for C-H amidation reactions involving weakly coordinating carbonyl-based directing groups with no acceleration observed for the corresponding reactions involving strongly coordinating nitrogen-based directing groups.
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Affiliation(s)
- Liselle Atkin
- Monash University MIPS: Monash Institute of Pharmaceutical Sciences, Department of Medicinal Chemistry, AUSTRALIA
| | - Daniel Priebbenow
- Monash University MIPS: Monash Institute of Pharmaceutical Sciences, Medicinal Chemistry, 381 Royal Pde, 3052, Parkville, AUSTRALIA
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Atkin L, Priebbenow DL. Cobalt-catalysed acyl silane directed ortho C–H functionalisation of benzoyl silanes. Chem Commun (Camb) 2022; 58:12604-12607. [DOI: 10.1039/d2cc05350k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acyl silanes can be engaged as weakly coordinating directing groups in cobalt catalysed C–H functionalisation reactions to prepare benzoyl silanes that are highly amenable to subsequent synthetic manipulations yet inaccessible via existing methods.
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Affiliation(s)
- Liselle Atkin
- Department of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Daniel L. Priebbenow
- Department of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
- School of Chemistry, University of Melbourne, Parkville, 3010, Victoria, Australia
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Abstract
The total synthesis of viridiofungins A (1) and B (2) via β-lactone 3 in 13 steps is reported. Key steps included an HF-mediated rearrangement of cyclobutene diester 9 to form a bicyclic lactone 6, an olefin cross metathesis between disubstituted alkene 3 and alkene 4 in which isomerization was suppressed, and a novel β-lactone ring opening to form the amide. Deprotection then gave either viridiofungin A (1) or B (2) in high yield.
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Affiliation(s)
- Liselle Atkin
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
| | - Angus Robertson
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
| | - Jonathan M White
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
| | - Mark A Rizzacasa
- School of Chemistry, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
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Pidot SJ, Herisse M, Sharkey L, Atkin L, Porter JL, Seemann T, Howden BP, Rizzacasa MA, Stinear TP. Biosynthesis and Ether‐Bridge Formation in Nargenicin Macrolides. Angew Chem Int Ed Engl 2019; 58:3996-4001. [DOI: 10.1002/anie.201900290] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Sacha J. Pidot
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Marion Herisse
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Liam Sharkey
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Liselle Atkin
- School of ChemistryThe Bio21 Molecular Science and Biotechnology InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Jessica L. Porter
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Torsten Seemann
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
- Microbioloigical Diagnostic UnitUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Benjamin P. Howden
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
- Microbioloigical Diagnostic UnitUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Mark A. Rizzacasa
- School of ChemistryThe Bio21 Molecular Science and Biotechnology InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
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Pidot SJ, Herisse M, Sharkey L, Atkin L, Porter JL, Seemann T, Howden BP, Rizzacasa MA, Stinear TP. Biosynthesis and Ether‐Bridge Formation in Nargenicin Macrolides. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sacha J. Pidot
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Marion Herisse
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Liam Sharkey
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Liselle Atkin
- School of ChemistryThe Bio21 Molecular Science and Biotechnology InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Jessica L. Porter
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Torsten Seemann
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
- Microbioloigical Diagnostic UnitUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Benjamin P. Howden
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
- Microbioloigical Diagnostic UnitUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Mark A. Rizzacasa
- School of ChemistryThe Bio21 Molecular Science and Biotechnology InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology at the Doherty InstituteUniversity of Melbourne Melbourne VIC 3000 Australia
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Atkin L, Chen Z, Robertson A, Sturgess D, White JM, Rizzacasa MA. Synthesis of Alkyl Citrates (-)-CJ-13,981, (-)-CJ-13,982, and (-)-L-731,120 via a Cyclobutene Diester. Org Lett 2018; 20:4255-4258. [PMID: 29953238 DOI: 10.1021/acs.orglett.8b01665] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient and step-economic new approach to alkyl citrate natural products from a cyclobutene diester is presented. The key sequence involves a formal [2 + 2]-cycloaddition of a silylketene acetal with dimethylacetylene dicarboxylate to provide the cyclobutene diester 14 with 4.5:1 stereoselectivity. Exposure of diester 14 in acidic methanol effected a hydrolysis, intramolecular oxy-Michael reaction, and cyclobutanone methanolysis cascade to give the triester 15. Iodination and elimination then afforded a key alkyl citrate alkene intermediate, which was converted into the natural products (-)-CJ-13,982 (1), (-)-CJ-13,981 (2), and (-)-L-731,120 (3) via a cross-metathesis and subsequent reduction.
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Affiliation(s)
- Liselle Atkin
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Zongjia Chen
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Angus Robertson
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Dayna Sturgess
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Jonathan M White
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Mark A Rizzacasa
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne , Melbourne , Victoria 3010 , Australia
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Caddy J, Singh N, Atkin L, Ahluwalia M, Roberts A, Lang D, Thomas AW, Webb R. Rosiglitazone transiently disturbs calcium homeostasis in monocytic cells. Biochem Biophys Res Commun 2007; 366:149-55. [PMID: 18053798 DOI: 10.1016/j.bbrc.2007.11.095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Accepted: 11/19/2007] [Indexed: 11/25/2022]
Abstract
The PPARgamma agonist Rosiglitazone exerts anti-hyperglycaemic effects by regulating the long-term expression of genes involved in metabolism, differentiation and inflammation. In the present study, Rosiglitazone treatment rapidly inhibited (5-30 min) the ER Ca(2+) ATPase SERCA2b in monocytic cells (IC(50)=1.88 microM; p<0.05), thereby disrupting short-term Ca(2+) homeostasis (resting [Ca(2+)](cyto)=121.2+/-2.9% basal within 1h; p<0.05). However, extended Rosiglitazone treatment (72 h) induced dose-dependent SERCA2b up-regulation, and restored calcium homeostasis, in monocytic cells (SERCA2b mRNA: 138.7+/-5.7% basal (1 microM)/215.0+/-30.9% basal (10 microM); resting [Ca(2+)](cyto)=97.3+/-8.3% basal (10 microM)). As unfavourable cardiovascular outcomes, possibly related to disrupted cellular Ca(2+) homeostasis, have been linked to Rosiglitazone, this effect may be of clinical interest. In contrast, in PPRE-luciferase reporter-gene assays, Rosiglitazone induced non-dose-dependent PPARgamma-dependent effects (1 microM: 152.5+/-4.9% basal; 10 microM: 136.1+/-5.1% basal (p<0.05 for 1 microM vs. 10 microM)). Thus, we conclude that Rosiglitazone can exert PPARgamma-independent non-genomic effects, such as the SERCA2b inhibition seen here, but that long-term Rosiglitazone treatment did not perturb resting [Ca](cyto) in this study.
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Affiliation(s)
- J Caddy
- Centre for Biomedical Sciences, Cardiff School of Health Sciences, University of Wales Institute Cardiff, Cardiff CF5 2YB, UK
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Batty LC, Atkin L, Manning DAC. Assessment of the ecological potential of mine-water treatment wetlands using a baseline survey of macroinvertebrate communities. Environ Pollut 2005; 138:412-9. [PMID: 15993527 DOI: 10.1016/j.envpol.2005.04.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Accepted: 04/22/2005] [Indexed: 05/03/2023]
Abstract
A baseline survey of macroinvertebrate populations in two mine-water treatment wetlands, one treating a net acidic spoil heap discharge and one a net alkaline ferruginous pumped mine water, was undertaken to assess the potential of these systems to provide habitats for faunal communities. Both wetlands were found to be impoverished in comparison to natural wetlands but did sustain a macroinvertebrate community that could support higher organisms. Wetland size and water quality in terms of pH, conductivity and metal concentrations were found to be important factors in determining the quality of the populations supported. Direct toxicity to organisms was unlikely to be the main cause of lower diversity, but the smothering of organisms via the precipitation of iron hydroxides particularly in the early parts of the treatment systems affected macroinvertebrate communities. The presence of areas of open water within the planted systems was found to be important for providing habitats for macroinvertebrates and this should be both a future design and maintenance consideration for environmental managers.
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Affiliation(s)
- L C Batty
- School of Civil Engineering and Geosciences, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK.
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Schneider J, Hallam A, Murray J, Foley B, Atkin L, Banerjee S, Islam MK, Mann A. Formal and informal care for people with dementia: factors associated with service receipt. Aging Ment Health 2002; 6:255-65. [PMID: 12217094 DOI: 10.1080/13607860220142486] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Details of service receipt by 132 people diagnosed with dementia and their carers were collected in South London (boroughs of Lewisham, Camberwell, Southwark and Croydon), a geographical area served by several health and social care providers. The data collected included the Caregiver Activity Survey, which details the informal care given. This paper reports the formal and informal services received by the people with dementia at entry to the study. The amount of time spent on specific caring tasks by all informal carers of people with dementia averaged seven hours per week, but was significantly higher for co-resident carers, even when controlling for the level of dependency of the person cared-for. The odds ratios of receipt of formal services are given, according to where people were living: in the community or residential care, with co-resident carers or alone.
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Affiliation(s)
- J Schneider
- Centre for Applied Social Studies, University of Durham., UK.
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Atkin L. Loss of body heat following surgical intervention. Nurs Times 1998; 94:56-7. [PMID: 9919257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Affiliation(s)
- L Atkin
- Recovery Unit, Princess Royal NHS Trust Hospital, Telford, Shropshire
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Abstract
AbstractInter-specific variation in copulation behaviour among birds is described. The following factors explaining variation in copulation rate are examined: (i) the number of eggs which have to be fertilized (the fertilization hypothesis), (ii) the importance of the pair-bond (the social bond hypothesis), (iii) predation risk during copulation (the predation hypothesis), and (iv) cuckoldry risk (the sperm competition hypothesis). These hypotheses were investigated in preliminary analyses at the generic level using data on copulation behaviour in 131 bird species. The sperm competition hypothesis was supported by several lines of evidence: (i) frequent copulations among genera where males are not able to guard their mates (colonial birds, diurnal birds of prey, and owls), (ii) frequent copulations in polyandrous genera, (iii) copulations inside hole-nests of colonial birds but outside the hole-nests of solitarily nesting genera, and (iv) by the occurrence of forced pair copulations following extra-pair copulation in some species. The predation and social bond hypotheses were not totally dismissed, but there was no evidence that fertilization ability was limited by copulation frequency (i.e. the fertilization hypothesis).
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Affiliation(s)
- A.P. Møller
- 1Institute of Zoology and Zoophysiology, Zoological Laboratory, University of Aarhus, DK-8000, Aarhus C, Denmark
| | - L. Atkin
- 2Department of Zoology, The University, Sheffield, S10 2TN, England
| | - T.R. Birkhead
- 3Department of Zoology, The University, Sheffield, S10 2TN, England
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Affiliation(s)
- L Atkin
- Wallerstein Laboratories, 180 Madison Avenue, New York 16, N. Y
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Affiliation(s)
- A S Schultz
- The Fleischmann Laboratories, Standard Brands Incorporated, New York, N. Y
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Affiliation(s)
- R. F. Light
- Fleischmann Laboratories, Standard Brands Incorporated, New York City
| | - A. S. Schultz
- Fleischmann Laboratories, Standard Brands Incorporated, New York City
| | - L. Atkin
- Fleischmann Laboratories, Standard Brands Incorporated, New York City
| | - L. J. Cracas
- Fleischmann Laboratories, Standard Brands Incorporated, New York City
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