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Abstract
Synthetic organic chemists have a long-standing appreciation for transition metal cyclopentadienyl complexes, of which many have been used as catalysts for organic transformations. Much less well known are the contributions of the benzo-fused relative of the cyclopentadienyl ligand, the indenyl ligand, whose unique properties have in many cases imparted differential reactivity in catalytic processes toward the synthesis of small molecules. In this Review, we present examples of indenylmetal complexes in catalysis and compare their reactivity to their cyclopentadienyl analogues, wherever possible.
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Affiliation(s)
- Barry M Trost
- Department of Chemistry, Stanford University, Stanford, CA, 94305-5080, USA
| | - Michael C Ryan
- Department of Chemistry, Stanford University, Stanford, CA, 94305-5080, USA
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2
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Affiliation(s)
- Shubhendu Dhara
- Schulich Faculty of Chemistry; Technion - Israel Institute of Technology; 3200003 Haifa Israel
| | - Charles E. Diesendruck
- Schulich Faculty of Chemistry; Technion - Israel Institute of Technology; 3200003 Haifa Israel
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3
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Affiliation(s)
- Barry M. Trost
- Department of Chemistry Stanford University Stanford CA 94305-5080 USA
| | - Michael C. Ryan
- Department of Chemistry Stanford University Stanford CA 94305-5080 USA
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4
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Xu S, Negishi EI. Zirconium-Catalyzed Asymmetric Carboalumination of Unactivated Terminal Alkenes. Acc Chem Res 2016; 49:2158-2168. [PMID: 27685327 DOI: 10.1021/acs.accounts.6b00338] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Carbometalation of alkenes with stereocontrol offers an important opportunity for asymmetric C-C bond formation. However, the scope of catalytic stereoselective carbometalation of alkenes had until recently been limited to electronically biased alkenes or those with the presence of directing groups or other auxiliary functionalities to overcome the challenge associated with regio- and stereoselectivity. Catalytic asymmetric carbometalation of unactivated alkenes on the other hand remained as a formidable challenge. To address this long-standing problem, we sought to develop Zr-catalyzed asymmetric carboalumination of alkenes (namely, ZACA reaction) encouraged by our discovery of Zr-catalyzed alkyne carboalumination in 1978. Zr-catalyzed methylalumination of alkynes (ZMA) shows high regioselectivity and nearly perfect stereoselectivity. Its mechanistic studies have revealed that the ZMA reaction involves acyclic carbometalation with "superacidic" bimetallic reagents generated by interaction between two Lewis acids, i.e., alkylalanes and 16-electron zirconocene derivatives through dynamic polarization and ate complexation, affectionately termed as the "two-is-better-than-one" principle. With the encouraging results of Zr-catalyzed carboalumination of alkynes in hand, we sought to develop its alkene version for discovering a catalytic asymmetric C-C bond-forming reaction by using alkylalanes and suitable chiral zirconocene derivatives, which would generate "superacidic" bimetallic species to promote the desired carbometalation of alkenes. However, this proved to be quite challenging. Three major competing side reactions occur, i.e., (i) β-H transfer hydrometalation, (ii) bimetallic cyclic carbometalation, and (iii) Ziegler-Natta polymerization. The ZACA reaction was finally discovered by employing Erker's (-)-(NMI)2ZrCl2 as the catalyst and chlorinated hydrocarbon as solvent to suppress the undesired side reactions mentioned above. The ZACA reaction has evolved as a powerful tool for the efficient preparation of a wide range of chiral natural products through the following methodological developments: (1) three mutually complementary protocols for methyl-branched chiral alkanols; (2) water, MAO, and IBAO as promoters to accelerate otherwise sluggish carboaluminations; (3) one-step homologation synthesis of deoxypropionates based on one-pot ZACA-Pd-catalyzed vinylation tandem process; (4) ZACA-lipase-catalyzed acetylation-transition-metal-catalyzed cross-coupling processes for preparing various virtually enantiopure chiral alcohols; (5) the chemoselective ZMA and ZACA reactions as well as alkyne elementometalation-Pd-catalyzed cross-coupling for constructing a variety of chiral compounds containing regio- and stereodefined substituted alkenes; (6) the ZACA reaction of dienes to generate chiral organocyclic compounds including those with all-carbon quaternary stereocenters.
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Affiliation(s)
- Shiqing Xu
- Herbert
C. Brown Laboratories
of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Ei-ichi Negishi
- Herbert
C. Brown Laboratories
of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
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5
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Lehmann J, Wright MH, Sieber SA. Making a Long Journey Short: Alkyne Functionalization of Natural Product Scaffolds. Chemistry 2016; 22:4666-78. [PMID: 26752308 DOI: 10.1002/chem.201504419] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Indexed: 01/09/2023]
Abstract
Biological selection makes natural products promising scaffolds for drug development and the ever growing number of newly identified, structurally diverse molecules helps to fill the gaps in chemical space. Elucidating the function of a small molecule, such as identifying its protein binding partners, its on- and off-targets, is becoming increasingly important. Activity- and affinity-based protein profiling are modern strategies to acquire such molecular-level information. Introduction of a molecular handle (azide, alkyne, biotin) can shed light on the mode of action of small molecules. This Concept article covers central points on synthetic methodology for integrating a terminal alkyne into a molecule of interest.
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Affiliation(s)
- Johannes Lehmann
- Center for Integrated Protein Science, Munich (CIPSM), Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Megan H Wright
- Center for Integrated Protein Science, Munich (CIPSM), Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Stephan A Sieber
- Center for Integrated Protein Science, Munich (CIPSM), Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany.
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Kim T, Han YT, An H, Kim K, Lee J, Suh YG. Diastereoselective Total Synthesis of (−)-Galiellalactone. J Org Chem 2015; 80:12193-200. [DOI: 10.1021/acs.joc.5b02121] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Taewoo Kim
- College
of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea
| | - Young Taek Han
- College
of Pharmacy, Dankook University, 119 Dandae-ro,
Dongnam-gu, Cheonan 330-714, Korea
| | - Hongchan An
- College
of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea
| | - Kyeojin Kim
- College
of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea
| | - Jeeyeon Lee
- College
of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea
| | - Young-Ger Suh
- College
of Pharmacy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea
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Yang J, Yin W, Liu R, Chu C. Ti(Oi-Pr)4Mediated Olefination between Julia Reagent and Aldehydes under Mild Conditions: Facile Synthesis of Vinyl Sulfones. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201200466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Biradar DB, Gau HM. An efficient nickel-catalyzed alkenylation of functionalized benzylic halides with alkenylaluminum reagents. Org Biomol Chem 2012; 10:4243-8. [DOI: 10.1039/c2ob25303h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Negishi EI. Magical power of transition metals: past, present, and future (Nobel Lecture). Angew Chem Int Ed Engl 2011; 50:6738-64. [PMID: 21717531 DOI: 10.1002/anie.201101380] [Citation(s) in RCA: 553] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Ei-ichi Negishi
- Herbert C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive,West Lafayette, IN 47907-2084, USA
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Negishi EI. Die magische Kraft der Übergangsmetalle: Vergangenheit, Gegenwart und Zukunft (Nobel-Aufsatz). Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101380] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Millar JG, McElfresh JS, Romero C, Vila M, Marí-Mena N, Lopez-Vaamonde C. Identification of the sex pheromone of a protected species, the Spanish moon moth Graellsia isabellae. J Chem Ecol 2010; 36:923-32. [PMID: 20658260 PMCID: PMC2941043 DOI: 10.1007/s10886-010-9831-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 06/21/2010] [Accepted: 07/02/2010] [Indexed: 11/27/2022]
Abstract
Sex attractant pheromones are highly sensitive and selective tools for detecting and monitoring populations of insects, yet there has been only one reported case of pheromones being used to monitor protected species. Here, we report the identification and synthesis of the sex pheromone of a protected European moth species, Graellsia isabellae (Lepidoptera: Saturniidae), as the single component, (4E,6E,11Z)-hexadecatrienal. In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species.
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Affiliation(s)
- Jocelyn G Millar
- Department of Entomology, University of California, Riverside, CA 92521, USA.
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Li Y, Liu X, Jiang H, Feng Z. Expedient Synthesis of Functionalized Conjugated Enynes: Palladium-Catalyzed Bromoalkynylation of Alkynes. Angew Chem Int Ed Engl 2010; 49:3338-41. [DOI: 10.1002/anie.201000003] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Li Y, Liu X, Jiang H, Feng Z. Expedient Synthesis of Functionalized Conjugated Enynes: Palladium-Catalyzed Bromoalkynylation of Alkynes. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201000003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Parfenova LV, Berestova TV, Tyumkina TV, Kovyazin PV, Khalilov LM, Whitby RJ, Dzhemilev UM. Enantioselectivity of chiral zirconocenes as catalysts in alkene hydro-, carbo- and cycloalumination reactions. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.tetasy.2010.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Negishi EI, Huang Z, Wang G, Mohan S, Wang C, Hattori H. Recent advances in efficient and selective synthesis of di-, tri-, and tetrasubstituted alkenes via Pd-catalyzed alkenylation-carbonyl olefination synergy. Acc Chem Res 2008; 41:1474-85. [PMID: 18783256 DOI: 10.1021/ar800038e] [Citation(s) in RCA: 372] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although generally considered competitive, the alkenylation and carbonyl olefination routes to alkenes are also complementary. In this Account, we focus on these approaches for the synthesis of regio- and stereodefined di- and trisubstituted alkenes and a few examples of tetrasubstituted alkenes. We also discuss the subset of regio- and stereodefined dienes and oligoenes that are conjugated. Pd-catalyzed cross-coupling using alkenyl metals containing Zn, Al, Zr, and B (Negishi coupling and Suzuki coupling) or alkenyl halides and related alkenyl electrophiles provides a method of alkenylation with the widest applicability and predictability, with high stereo- and regioselectivity. The requisite alkenyl metals or alkenyl electrophiles are most commonly prepared through highly selective alkyne addition reactions including (i) conventional polar additions, (ii) hydrometalation, (iii) carbometalation, (iv) halometalation, and (v) other heteroatom-metal additions. Although much more limited in applicability, the Heck alkenylation offers an operationally simpler, viable alternative when it is highly selective and satisfactory. A wide variety of carbonyl olefination reactions, especially the Wittig olefination and its modifications represented by the E-selective HWE olefination and the Z-selective Still-Gennari olefination, collectively offer the major alternative to the Pd-catalyzed alkenylation. However, the carbonyl olefination method fundamentally suffers from more limited stereochemical options and generally lower stereoselectivity levels than the Pd-catalyzed alkenylation. In a number of cases, however, very high (>98%) stereoselectivity levels have been attained in the syntheses of both E and Z isomers. The complementarity of the alkenylation and carbonyl olefination routes provide synthetic chemists with valuable options. While the alkenylation involves formation of a C-C single bond to a CC bond, the carbonyl olefination converts a CO bond to a CC bond. When a precursor to the desired alkene is readily available as an aldehyde, the carbonyl olefination is generally the more convenient of the two. This is a particularly important factor in many cases where the desired alkene contains an allylic asymmetric carbon center, since alpha-chiral aldehydes can be prepared by a variety of known asymmetric methods and readily converted to allylically chiral alkenes via carbonyl olefination. On the other hand, a homoallylically carbon-branched asymmetric center can be readily installed by either Pd-catalyzed isoalkyl-alkenyl coupling or Zr-catalyzed asymmetric carboalumination (ZACA reaction) of 1,4-dienes. In short, it takes all kinds to make alkenes, just as it takes all kinds to make the world.
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Affiliation(s)
- Ei-ichi Negishi
- H. C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084
| | - Zhihong Huang
- H. C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084
| | - Guangwei Wang
- H. C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084
| | - Swathi Mohan
- H. C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084
| | - Chao Wang
- H. C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084
| | - Hatsuhiko Hattori
- H. C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084
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Metzger A, Schade M, Manolikakes G, Knochel P. A General Preparation of Polyfunctional Benzylic Zinc Organometallic Compounds. Chem Asian J 2008; 3:1678-91. [DOI: 10.1002/asia.200800161] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Wang G, Huang Z, Negishi EI. Efficient and selective syntheses of (all-E)- and (6E,10Z)-2'-O-methylmyxalamides D via Pd-catalyzed alkenylation--carbonyl olefination synergy. Org Lett 2008; 10:3223-6. [PMID: 18593171 DOI: 10.1021/ol801115s] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Highly efficient and selective syntheses of both (all- E) and (6 E,10 Z)-isomers of 2'- O-methylmyxalamide D ( 2 and 3), in which the crucial conjugated pentaene moieties were assembled in > or =98% stereoselectivity through the use of two Pd-catalyzed alkenylation reactions, the Horner-Wadsworth-Emmons (HWE) olefination, and either the Corey-Schlessinger-Mills modified (CSM-modified) Peterson olefination for 2 or the Still-Gennari olefination for 3, are reported. Either 2 or 3 was prepared in 16% yield in seven steps from propargyl alcohol.
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Affiliation(s)
- Guangwei Wang
- Herbert C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, USA
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Huang Z, Tan Z, Novak T, Zhu G, Negishi EI. Zirconium-Catalyzed Asymmetric Carboalumination of Alkenes: ZACA–Lipase-Catalyzed Acetylation Synergy. Adv Synth Catal 2007. [DOI: 10.1002/adsc.200600548] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Negishi EI. Transition Metal-Catalyzed Organometallic Reactions that Have Revolutionized Organic Synthesis. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.233] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Hypervalent organoantimony compounds 12-ethynyl-tetrahydrodibenz[c,f][1,5]azastibocines: Highly efficient new transmetallating agent for organic halides. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2006.02.041] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Palladium-catalyzed desulfinylative Negishi C–C bond forming cross-couplings of sulfonyl and organozinc chlorides. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.03.101] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Cooksey JP, Kocienski PJ, Li YF, Schunk S, Snaddon TN. Synthesis of the C1–C16 fragment of ionomycin using a neutral (η3-allyl)iron complex. Org Biomol Chem 2006; 4:3325-36. [PMID: 17036122 DOI: 10.1039/b606262h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Key steps in the synthesis of the C1-C16 polyketide fragment of ionomycin were the nucleophilic addition of an organocuprate to a neutral (eta3-allyl)iron complex and the construction of a beta-diketone moiety by the Rh-catalysed rearrangement of an alpha-diazo-beta-hydroxyketone.
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Gavryushin A, Kofink C, Manolikakes G, Knochel P. Efficient Cross-Coupling of Functionalized Arylzinc Halides Catalyzed by a Nickel Chloride−Diethyl Phosphite System. Org Lett 2005; 7:4871-4. [PMID: 16235910 DOI: 10.1021/ol051615+] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] The combination of diethyl phosphite and DMAP as ligands for nickel in an 8:1 THF-N-ethylpyrrolidinone (NEP) mixture allows a very efficient cross-coupling reaction to be performed between various functionalized arylzinc halides and aryl bromides, triflates and activated chlorides. The reaction proceeds at 25 degrees C within 1-48 h and requires only 0.05 mol % of the nickel catalyst.
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van Summeren RP, Feringa BL, Minnaard AJ. New approaches towards the synthesis of the side-chain of mycolactones A and B. Org Biomol Chem 2005; 3:2524-33. [PMID: 15999184 DOI: 10.1039/b505980a] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New approaches towards the synthesis of the C1'-C16' side-chain of mycolactones A and B from Mycobacterium ulcerans are reported. Chiral building block 4 (Fig. 2) with the correct stereochemistry was obtained starting from naturally occurring monosaccharides, i.e. D-glucose or L-rhamnose. The polyunsaturated moiety 3 was synthesized in only 3 steps from 2,4-dimethylfuran. The building blocks were connected through a Sonogashira coupling resulting in the fast and convergent assembly of an 8,9-dehydro analogue 2 of the side-chain of mycolactones A and B. The synthesis of 1 is at this stage hampered by the lack of a selective partial hydrogenation protocol for alkynes embedded in a conjugated system. Alternative strategies involving palladium catalyzed sp2-sp2 coupling between C7' and C8' or C9' and C10' (Fig. 1) were also explored.
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Affiliation(s)
- Ruben P van Summeren
- Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
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Ramachandran PV, Burghardt TE. Highly Diastereoselective and Enantioselective Preparation of Homoallylic Amines: Application for the Synthesis of β-Amino Acids and γ-Lactams. Chemistry 2005; 11:4387-95. [PMID: 15880541 DOI: 10.1002/chem.200401295] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Reactions of N-silyl- and N-aluminoimines with B-allyldiisopinocampheylborane in the presence of methanol, followed by oxidative workup furnished homoallylic amines in good yields and high ee. A 11B NMR spectroscopy study revealed that the reactions do not proceed, even at room temperature, unless a molar equivalent of water or methanol is added. The first reagent-controlled asymmetric crotylboration and alkoxyallylboration of aldimines furnishing beta-methyl or beta-alkoxy homoallylic amines in very high diastereoselectivity and enantioselectivity are reported herein. Crotylboration and alkoxyallylboration of imines proceed only with the "allyl"-boron "ate" complexes, instead of the "allyl"-dialkylboron reagents used with aldehydes. The addition of methanol is necessary for these reactions as well. Application of this methodology for the conversion of representative nitriles to beta-amino acids in two steps has been described. Additionally, a procedure for the preparation of chiral delta-amino alcohols and gamma-lactams from nitriles is also reported.
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Affiliation(s)
- P Veeraraghavan Ramachandran
- Herbert C. Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, IN 47907-2084, USA
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Abstract
Systematic explorations of organozirconium chemistry over the past quarter of a century have led to the discoveries and development as well as structural and mechanistic clarifications of novel Zr-catalyzed and -promoted carbon-carbon bond-forming reactions including (i) Ni- or Pd-catalyzed cross-coupling reaction of organozirconiums, (ii) Zr-catalyzed carboalumination of alkynes, (iii) Zr-catalyzed asymmetric carboalumination of alkenes, (iv) generation and carbometallative ring expansion of zirconacyclopropanes and zirconacyclopropenes and a myriad of their transformations and (v) various organozirconium migratory insertion reactions.
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Affiliation(s)
- Ei-ichi Negishi
- Herbert C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, USA.
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