1
|
Zheng J, Peters BBC, Jiang W, Suàrez LA, Ahlquist MSG, Singh T, Andersson PG. The Effect of Conformational Freedom vs Restriction on the Rate in Asymmetric Hydrogenation: Iridium-Catalyzed Regio- and Enantioselective Monohydrogenation of Dienones. Chemistry 2023:e202303406. [PMID: 38109038 DOI: 10.1002/chem.202303406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 12/19/2023]
Abstract
Transition metal-catalyzed asymmetric hydrogenation constitutes an efficient strategy for the preparation of chiral molecules. When dienes are subjected to hydrogenation, control over regioselectivity still presents a large challenge and the fully saturated alkane is often yielded. A few successful monohydrogenations of dienes have been reported, but hitherto these are only efficient for dienes comprised of two distinctly different olefins. Herein, the reactivity of a conjugated carbonyl compound as a function of their conformational freedom is studied, based on a combined experimental and theoretical approach. It was found that alkenes in the (s)-cis conformation experience a large rate acceleration while (s)-trans restrained alkenes undergo hydrogenation slowly. Ultimately, this reactivity aspect was exploited in a novel method for the monohydrogenation of dienes based on conformational restriction ((s)-cis vs (s)-trans). This mode of discrimination conceptually differs from existing monohydrogenations and dienones constructed of two olefins similar in nature could efficiently be hydrogenated to the chiral alkene (up to 99 % ee). The extent of regioselection is even powerful enough to overcome the conventional reactivity order of substituted olefins (di>tri>tetra). This high yielding and atom-economical protocol provides an interesting opportunity to instal a stereogenic center on a carbocycle, while leaving a synthetically useful alkene untouched.
Collapse
Affiliation(s)
- Jia Zheng
- Department of Organic Chemistry, Stockholm University, 10691, Stockholm, Sweden
| | - Bram B C Peters
- Department of Organic Chemistry, Stockholm University, 10691, Stockholm, Sweden
| | - Wei Jiang
- Department of Organic Chemistry, Stockholm University, 10691, Stockholm, Sweden
| | - Lluís Artús Suàrez
- School of Biotechnology, KTH Royal Institute of Technology, 10691, Stockholm, Sweden
| | - Mårten S G Ahlquist
- School of Biotechnology, KTH Royal Institute of Technology, 10691, Stockholm, Sweden
| | - Thishana Singh
- School of Chemistry and Physics, University of Kwazulu-Natal, Private Bag X54001, 4000, Durban, South Africa
| | - Pher G Andersson
- Department of Organic Chemistry, Stockholm University, 10691, Stockholm, Sweden
- School of Chemistry and Physics, University of Kwazulu-Natal, Private Bag X54001, 4000, Durban, South Africa
| |
Collapse
|
2
|
Helmchen G. Mechanistic Aspects of the Crabtree-Pfaltz Hydrogenation of Olefins - An Interplay of Experimentation and Quantum Chemical Computation. Chemistry 2023; 29:e202301488. [PMID: 37363889 DOI: 10.1002/chem.202301488] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 06/28/2023]
Abstract
Introduction of Crabtree's iridium-based hydrogenation catalyst in 1977 marked a paradigm shift both with respect to the role of iridium in homogeneous catalysis as well as catalytic hydrogenation of olefins. In 1998, Pfaltz introduced an improved catalyst, by use of BARF- as anion, and established the first chiral variant of the Crabtree catalyst. This led to numerous practical highly enantioselective syntheses. Elucidation of mechanistic details posed great problems because of instability of the crucial intermediates. A remarkable breakthrough was achieved by Brandt, Andersson et al. in 2003, based on dft calculations. These authors replaced a previously assumed IrI /IrIII catalytic cycle by a novel IrIII /IrV cycle. The proposal was experimentally verified by Pfaltz in 2014 and corroborated by advanced quantum chemical calculations. This essay is an attempt to describe a fascinating interplay of experiments and quantum chemical calculations for an important synthetic method.
Collapse
Affiliation(s)
- Günter Helmchen
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| |
Collapse
|
3
|
Oka S, Watanabe M, Ito E, Takeyama A, Matsuoka T, Takahashi M, Izumi Y, Arichi N, Ohno H, Yamasaki S, Inuki S. Archaeal Glycerolipids Are Recognized by C-Type Lectin Receptor Mincle. J Am Chem Soc 2023; 145:18538-18548. [PMID: 37555666 DOI: 10.1021/jacs.3c05473] [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: 08/10/2023]
Abstract
Recently, various metabolites derived from host microbes have been reported to modulate the immune system, with potential involvement in health or diseases. Archaea, prokaryotic organisms, are present in the human body, but their connection with the host is largely unknown when compared to other microorganisms such as bacteria. This study focused on unique glycerolipids from symbiotic methanogenic archaea and evaluated their activities toward an innate immune receptor. The results revealed that archaeal lipids were recognized by the C-type lectin receptor Mincle and induced immune responses. A concurrent structure-activity relationship study identified the key structural features of archaeal lipids required for recognition by Mincle. Subsequent gene expression profiling suggested qualitative differences between the symbiotic archaeal lipid and the pathogenic bacteria-derived lipid. These findings have broad implications for understanding the function of symbiotic archaea in host health and diseases.
Collapse
Affiliation(s)
- Shiori Oka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| | - Miyuki Watanabe
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka 565-0871, Japan
| | - Emi Ito
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka 565-0871, Japan
| | - Ami Takeyama
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka 565-0871, Japan
| | - Takuro Matsuoka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| | - Masatomo Takahashi
- Division of Metabolomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka 812-8582, Japan
| | - Yoshihiro Izumi
- Division of Metabolomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Fukuoka 812-8582, Japan
| | - Norihito Arichi
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| | - Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| | - Sho Yamasaki
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka 565-0871, Japan
| | - Shinsuke Inuki
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Kyoto 606-8501, Japan
| |
Collapse
|
4
|
Santhosh PB, Genova J. Archaeosomes: New Generation of Liposomes Based on Archaeal Lipids for Drug Delivery and Biomedical Applications. ACS OMEGA 2023; 8:1-9. [PMID: 36643444 PMCID: PMC9835528 DOI: 10.1021/acsomega.2c06034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Archaeosomes are a new generation of stable liposomes composed of natural ether lipids extracted from archaea, or synthetic archaeal lipids. Archaea constitute a domain of single-celled microorganisms that are structurally similar to but evolutionarily distinct from bacteria. They synthesize unique membrane lipids with isoprenoid hydrocarbon side chains attached via an ether linkage to the glycerol-phosphate backbone. Compared to the ester linkages found in the lipids of Eukarya and bacteria, the ether linkages in archaeal lipids are more stable in various environmental conditions such as high/low temperatures, acidic or alkaline pH, bile salts, and enzymatic hydrolysis. This feature has intrigued scientists to use archaeal lipids to prepare archaeosomes with superior physicochemical stability and utilize them as effective carriers to deliver various cargos of biomedical importance such as drugs, proteins, peptides, genes, and antioxidants to the target site. Archaeosomes carrying antigens and/or adjuvants are also proven to be better candidates for stimulating antigen-specific, humoral, and cell-mediated immune responses, which broadens their scope in vaccine delivery. These properties associated with excellent biocompatibility and a safety profile provide numerous advantages to the archaeosomes to function as a versatile delivery system. This mini-review will provide an overview of the unique features of archaeal lipids, preparation and characterization of archaeosomes, and emphasize the prospects related to drug delivery and other biomedical applications.
Collapse
|
5
|
Andringa RLH, Jonker M, Minnaard AJ. Synthesis of phosphatidic acids via cobalt(salen) catalyzed epoxide ring-opening with dibenzyl phosphate. Org Biomol Chem 2022; 20:2200-2204. [PMID: 35253820 PMCID: PMC8924959 DOI: 10.1039/d2ob00168c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
With a CoIII(salen)OTs catalyst, dibenzyl phosphate ring-opens a variety of terminal epoxides with excellent regio-selectively and yields up to 85%. The reaction is used in a highly efficient synthesis of enantiopure mixed-diacyl phosphatidic acids, including a photoswitchable phosphatidic acid mimic. A cobalt-catalyzed, phosphate-induced, ring-opening reaction is used in an efficient synthesis of enantiopure mixed-diacyl phosphatidic acids, including a photoswitchable phosphatidic acid mimic.![]()
Collapse
Affiliation(s)
- Ruben L H Andringa
- Stratingh Institute for Chemistry, University of Groningen Nijenborgh 7, 9747AG, Groningen, The Netherlands.
| | - Marijn Jonker
- Stratingh Institute for Chemistry, University of Groningen Nijenborgh 7, 9747AG, Groningen, The Netherlands.
| | - Adriaan J Minnaard
- Stratingh Institute for Chemistry, University of Groningen Nijenborgh 7, 9747AG, Groningen, The Netherlands.
| |
Collapse
|
6
|
Holzheimer M, Buter J, Minnaard AJ. Chemical Synthesis of Cell Wall Constituents of Mycobacterium tuberculosis. Chem Rev 2021; 121:9554-9643. [PMID: 34190544 PMCID: PMC8361437 DOI: 10.1021/acs.chemrev.1c00043] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
The pathogen Mycobacterium tuberculosis (Mtb), causing
tuberculosis disease, features an extraordinary
thick cell envelope, rich in Mtb-specific lipids,
glycolipids, and glycans. These cell wall components are often directly
involved in host–pathogen interaction and recognition, intracellular
survival, and virulence. For decades, these mycobacterial natural
products have been of great interest for immunology and synthetic
chemistry alike, due to their complex molecular structure and the
biological functions arising from it. The synthesis of many of these
constituents has been achieved and aided the elucidation of their
function by utilizing the synthetic material to study Mtb immunology. This review summarizes the synthetic efforts of a quarter
century of total synthesis and highlights how the synthesis layed
the foundation for immunological studies as well as drove the field
of organic synthesis and catalysis to efficiently access these complex
natural products.
Collapse
Affiliation(s)
- Mira Holzheimer
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Jeffrey Buter
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Adriaan J Minnaard
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| |
Collapse
|
7
|
Andringa RLH, de Kok NAW, Driessen AJM, Minnaard AJ. A Unified Approach for the Total Synthesis of cyclo-Archaeol, iso-Caldarchaeol, Caldarchaeol, and Mycoketide. Angew Chem Int Ed Engl 2021; 60:17497-17503. [PMID: 33929790 PMCID: PMC8362178 DOI: 10.1002/anie.202104759] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Indexed: 12/25/2022]
Abstract
Ir‐catalyzed asymmetric alkene hydrogenation is presented as the strategy par excellence to prepare saturated isoprenoids and mycoketides. This highly stereoselective synthesis approach is combined with an established 13C‐NMR method to determine the enantioselectivity of each methyl‐branched stereocenter. It is shown that this analysis is fit for purpose and the combination allows the synthesis of the title compounds with a significant increase in efficiency.
Collapse
Affiliation(s)
- Ruben L H Andringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Niels A W de Kok
- Department of Molecular Microbiology, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Arnold J M Driessen
- Department of Molecular Microbiology, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Adriaan J Minnaard
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| |
Collapse
|