Enantioselective synthesis of the C11-C24 segment of macrolactin a via organoiron methodology

Prahlad, V.; Donaldson, William A.

doi:10.1016/s0040-4039(96)02150-8

Cited by 37 publications

(8 citation statements)

References 18 publications

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“…Olefin insertion into the Feacyl bond generates the Fe-alkyl complex 23 which is in equilibrium with the Fe-enolate species 24 via β-hydride elimination/reinsertion steps. dine (78-89%) [29,30], or Ag 2 CO 3 (56%) [31]. A novel chemoselective, metal-mediated, oxidation of 1˚ or 2˚ alcohols adjacent to a (diene)Fe(CO) 3 group uses amine N-oxides (Scheme 4) [32].…”

Section: Methods For Liberation Of Diene Ligandmentioning

confidence: 99%

“…Alcohol oxidation, in the presence of a (diene)Fe(CO) 3 moiety has been successfully accomplished with PDC/4Å sieves (60%) [26], MnO 2 (60-80%) [27], DMSO/(COCl) 2 /NEt 3 (67-71%) [28], SO 3 -pyr (54-65%) [29], nPrMgBr/1,1'-(azodicarbonyl)dipiperi- …”

Section: Methods For Liberation Of Diene Ligandmentioning

confidence: 99%

“…the C11-C24 fragment of macrolactin A [29]. In contrast to the reactivity of 36, intramolecular nitrile oxide-olefin cyclo-addition for "skipped" triene complex 37 gave an equimolar mixture of diastereomers (eqn.…”

Section: S-trans S-cismentioning

confidence: 98%

“…acetate)iron complexes (83) in the presence of protic or Lewis acids, with weak hydride nucleophilies [25b, 29,89] or weak carbon nucleophiles [81,90] gives (E,E-diene)Fe(CO) 3 products 84, 85, and 86 (Scheme 21). The stereoselective substitution of dienol complexes 87 using (diethylamino)sulfur trifluoride [DAST], proceeding via…”

Section: Substitution Of (Dienol)-and (Di-enyl Actate)fe(co) 3 Complexesmentioning

confidence: 99%

“…Prahlad and Donaldson have reported an enantioenriched synthesis of the C11-C24 segment which utilizes organoiron methodology (Scheme 26) [29,54]. This synthesis also begins with racemic 41, however reaction with…”

Section: Synthetic Applications Which Make Multiple Use Of (Diene)iromentioning

confidence: 99%

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Stoichiometric Applications of Acyclic π-Organoiron Complexes to Organic Synthesis

Donaldson¹

2000

COC

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Abstract:The application of acyclic (diene)iron complexes and (pentadienyl)iron cations in organic synthesis has steadily increased over the past 20 years. This is due to their ease of preparation, their stability toward a wide variety of reaction conditions, the manifold method for removal of the Fe(CO) 3 group, and the low cost of iron carbonyls. The (tricarbonyl)iron adjunct may serve in three capacities: i) as a protecting group for conjugated dienes, ii) to direct the formation of chiral centers adjacent to the complexed dient, and iii) to stabilize the formation of positive charge adjacent ot the complexed diene (i.e. pentadienyl cations). Specific examples of these attributes will be presented in this review. One of the advantages of stoichiometric organometallic reagents is the ability to repeatedly utilize the same metal center to control a number of different bond forming reactions. Six examples will be presented which demonstrate this potential for acyclic (diene)iron complexes and (pentadienyl) iron cations.

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Section: Methods For Liberation Of Diene Ligandmentioning

confidence: 99%

Section: Methods For Liberation Of Diene Ligandmentioning

confidence: 99%

Section: S-trans S-cismentioning

confidence: 98%

Section: Substitution Of (Dienol)-and (Di-enyl Actate)fe(co) 3 Complexesmentioning

confidence: 99%

Section: Synthetic Applications Which Make Multiple Use Of (Diene)iromentioning

confidence: 99%

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Stoichiometric Applications of Acyclic π-Organoiron Complexes to Organic Synthesis

Donaldson¹

2000

COC

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Structural and Energetical Characterization of the Methylbutadiene–Fe(CO)3 Isomers and Related Reactive Intermediates with Quantum Chemical Methods

Pfletschinger

Schmalz²,

Koch³

1999

Eur. J. Inorg. Chem.

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A theoretical investigation of isoprene–Fe(CO)3 (2), (E)‐1,3‐pentadiene–Fe(CO)3 (3), (Z)‐1,3‐pentadiene–Fe(CO)3 (4), and reactive intermediates derived from these complexes was undertaken, employing the HF/DFT hybrid functional Becke3LYP, and the results are presented. Special emphasis is placed on cationic, anionic, and radical intermediates formally derived by abstraction of a hydride, a proton, or a hydrogen atom from the methyl group of the parent complexes. The geometry, energy, and electronic situation of the calculated species are discussed in the context of experimental facts. This leads to a better mechanistic understanding of the chemistry of acyclic butadiene–Fe(CO)3 complexes, provides insights into structural details of the intermediates involved, and allows the evaluation of possible resonance formulae. The calculation of transition states of isomerization (or racemization) processes even permits a quantitative description of energy profiles. In this way, the configurational stability of relevant cationic, anionic and radical intermediates can be estimated.

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Allylboration of Carbonyl Compounds

Lachance

Hall

2009

Organic Reactions

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Allylic boron compounds have gained a prominent status in organic synthesis for their ability to add with high stereoselectivity to carbonyl compounds such as aldehydes, making them a methodology of choice for the preparation of acetate and propionate units found in several classes of natural products. This remarkable reaction process was discovered in 1964, only to become popular in the 1980s. Using either the dialkylborane or boronate reagents, both the thermal uncatalyzed reaction and the more recent acid‐catalyzed procedures can provide homoallylic alcohol products in high enantioselectivity. The wide of range of possibilities for substitution on the reagent's allylic unit has led to the development of numerous reagents, and the residual alkene unit in the products confers to allylboration chemistry a unique versatility. This chapter presents an exhaustive survey of the useful reagents and their associated carbonyl substrates employed in organic synthesis. The mechanisms and parameters of the reaction are discussed, along with an overview of the different preparative methods for allylic boron reagents. The scope and limitations of these reagents in enantioselective additions, doubly diastereoselective additions, tandem reactions, and other variants is emphasized in the context of applications in natural product synthesis. The literature is covered through early 2006.

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Enantioselective synthesis of the C11-C24 segment of macrolactin a via organoiron methodology

Cited by 37 publications

References 18 publications

Stoichiometric Applications of Acyclic π-Organoiron Complexes to Organic Synthesis

Stoichiometric Applications of Acyclic π-Organoiron Complexes to Organic Synthesis

Structural and Energetical Characterization of the Methylbutadiene–Fe(CO)3 Isomers and Related Reactive Intermediates with Quantum Chemical Methods

Allylboration of Carbonyl Compounds

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Enantioselective synthesis of the C11-C24 segment of macrolactin a via organoiron methodology

Cited by 37 publications

References 18 publications

Stoichiometric Applications of Acyclic &#960;-Organoiron Complexes to Organic Synthesis

Stoichiometric Applications of Acyclic &#960;-Organoiron Complexes to Organic Synthesis

Structural and Energetical Characterization of the Methylbutadiene–Fe(CO)3 Isomers and Related Reactive Intermediates with Quantum Chemical Methods

Allylboration of Carbonyl Compounds

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Product

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Stoichiometric Applications of Acyclic π-Organoiron Complexes to Organic Synthesis

Stoichiometric Applications of Acyclic π-Organoiron Complexes to Organic Synthesis