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Alphand V.,CNRS Institute of Molecular Sciences of Marseilles | Wohlgemuth R.,Sigma-Aldrich
Current Organic Chemistry | Year: 2010

The knowledge about these Baeyer-Villiger monooxygenases has grown tremendously since the first discovery and fundamental progress in the understanding of structure, function, substrate specificities and other enzyme properties has been facilitated by the development of recombinant biocatalysts. Nature uses these biocatalysts in aerobic biodegradation pathways of cyclic and acyclic ketones and in the biosynthetic pathways of natural products. The excellent performance of Baeyer-Villiger monooxygenases in nature for the catalysis of Baeyer-Villiger oxidations with high chemo-, regio- and enantioselectivity is a role model for sustainable catalytic Baeyer-Villiger oxidations in organic synthesis. A broad range of biocatalytic conversions of cyclic ketones to lactones, linear ketones to esters, sulfoxidations and other oxidations is described. Applications in dynamic kinetic resolution as well as process and scale-up issues have been important in making this reaction platform attractive to industrial scale Baeyer-Villiger oxidations. New discoveries of Baeyer-Villiger monooxygenases in biosynthesis are promising for highly selective oxidations. © 2010 Bentham Science Publishers Ltd.


Clavier H.,University of St. Andrews | Clavier H.,CNRS Institute of Molecular Sciences of Marseilles | Nolan S.P.,University of St. Andrews
Chemical Communications | Year: 2010

Electronic and steric ligand effects both play major roles in organometallic chemistry and consequently in metal-mediated catalysis. Quantifying such parameters is of interest to better understand not only the parameters governing catalyst performance but also reaction mechanisms. Nowadays, ligand molecular architectures are becoming significantly more elaborate and existing models describing ligand sterics prove lacking. This review presents the development of a more general method to determine the steric parameter of organometallic ligands. Two case studies are presented: the tertiary phosphines and the N-heterocyclic carbenes. © The Royal Society of Chemistry 2010.


Nolan S.P.,University of St. Andrews | Clavier H.,CNRS Institute of Molecular Sciences of Marseilles
Chemical Society Reviews | Year: 2010

Over the past decade, ruthenium-mediated metathesis transformations, including polymerization reactions, cross-metathesis, ring-closing metathesis, enyne metathesis, ring-rearrangement metathesis, and also tandem processes, represent one of the most studied families of organic reactions. This has translated into the development of a large number of structurally diverse catalysts. Whereas most of these investigations are focused on determining catalytic performance, only rare examples of studies dealing with chemoselectivity have been reported to date. Usually, variations are observed in product conversions but rarely in product distributions. In this critical review, we provide an overview of the stereochemistry of newly formed C=C bonds either in ring-closing or cross-metathesis as a function of the catalyst structure. A discussion of disparities encountered in macrocyclisation reactions leading (or not) to the formation of dimeric products is also presented. Since distinctive metathesis products could be isolated as a function of the ligand borne by the ruthenium centre - phosphine or N-heterocyclic carbene in the dissymetrization of trienes, enyne metathesis and ring rearrangements, these topics are also discussed (72 references). © 2010 The Royal Society of Chemistry.


Audran G.,CNRS Institute of Molecular Sciences of Marseilles | Pellissier H.,CNRS Institute of Molecular Sciences of Marseilles
Advanced Synthesis and Catalysis | Year: 2010

Since the methylenecyclopropane moiety is found in many biologically active natural substances, the synthesis of methylene- and alkylidenecyclopropanes remains a considerable challenge. In addition, an attractive feature is their surprising stability, accompanied by a high level of strain, conferring on them an otherwise unattainable chemical reactivity. The growing interest in the chemistry of these compounds has in its turn stimulated the development of alternative approaches to their skeleton, aimed at selectively introducing structural and chemical diversification. The three principal methods to synthesize these important compounds are based on the formation of the cyclopropane ring, the use of preformed cyclopropanes, and the use of preformed methyleneand alkylidenecyclopropanes. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Bartoli A.,CNRS Institute of Molecular Sciences of Marseilles | Chouraqui G.,CNRS Institute of Molecular Sciences of Marseilles | Parrain J.-L.,CNRS Institute of Molecular Sciences of Marseilles
Organic Letters | Year: 2012

A concise route to the ABC and ABCD core of molecules isolated from the genus Schisandra has been accomplished. The synthesis demonstrated high atom efficiency employing a new one-pot cascade which sequentially built three rings and a quaternary spirocenter. © 2011 American Chemical Society.


Ibrahim-Ouali M.,CNRS Institute of Molecular Sciences of Marseilles
Tetrahedron Letters | Year: 2010

The first total synthesis of 11-tellura steroids was achieved via an intramolecular Diels-Alder cycloaddition of o-quinodimethanes as the key step. © 2010 Elsevier Ltd.


Manjunatha Reddy G.N.,CNRS Institute of Molecular Sciences of Marseilles | Caldarelli S.,CNRS Institute of Molecular Sciences of Marseilles
Analytical Chemistry | Year: 2010

We introduce an NMR method to help in the analysis of complex mixtures. The spectra of molecular fragments are obtained as the traces of a correlation spectrum of the regular 1H NMR spectrum on one dimension with the one of the highest possible 1H multiple-quantum (MaxQ) order. As this latter is a function of the number of distinguishable protons in a given molecular fragment, the analysis of a series of multiple-quantum spectra is required to achieve a complete assignment. This MaxQ NMR approach is likely to perform best in the case of signals concentrated in a very narrow frequency range, which is a challenging situation commonly encountered in many relevant analytical problems such as the characterization of extraction fractions (oil, plants, tissues), biological fluids, or environmentally relevant samples. As a demonstration, we apply the MaxQ NMR analysis to a mixture of 11 poly- and monocyclic aromatic hydrocarbons. © 2010 American Chemical Society.


Isambert N.,CNRS Institute of Molecular Sciences of Marseilles | Duque M.D.M.S.,CNRS Institute of Molecular Sciences of Marseilles | Plaquevent J.-C.,University Paul Sabatier | Genisson Y.,University Paul Sabatier | And 2 more authors.
Chemical Society Reviews | Year: 2011

The efficiency of a chemical synthesis can be nowadays measured, not only by parameters like selectivity and overall yield, but also by its raw material, time, human resources and energy requirements, as well as the toxicity and hazard of the chemicals and the protocols involved. The development of multicomponent reactions (MCRs) in the presence of task-specific ionic liquids (ILs), used not only as environmentally benign reaction media, but also as catalysts, is a new approach that meet with the requirements of sustainable chemistry. The aim of this tutorial review is to highlight the synergistic effect of the combined use of MCRs and ILs for the development of new eco-compatible methodologies for heterocyclic chemistry. © 2011 The Royal Society of Chemistry.


Pellissier H.,CNRS Institute of Molecular Sciences of Marseilles
Advanced Synthesis and Catalysis | Year: 2011

While tremendous advances have been made in asymmetric synthesis, the resolution of racemates is still the most important industrial approach to the synthesis of chiral compounds. The use of enzymes for the kinetic resolution (KR) of racemic substrates to afford enantiopure compounds in high enantioselectivity and good yield has long been a popular strategy in synthesis. However, transition metal-mediated and more recently organocatalyzed KRs have gained popularity within the synthetic community over the last two decades due to the progress made in the development of chiral catalysts for asymmetric reactions. Many catalytic non-enzymatic procedures have been developed providing high enantioselectivity and yield for both products and recovered starting materials. Indeed, the non-enzymatic KR of racemic compounds based on the use of a chiral catalyst is presently an area of great importance in asymmetric organic synthesis. The goal of this review is to provide an update on the principal developments of catalytic non-enzymatic KR covering the literature since 2004. This review is subdivided into seven sections, according to the different types of compounds that have been resolved through catalytic non-enzymatic KR, such as alcohols, epoxides, amines, alkenes, carbonyl derivatives, sulfur compounds and ferrocenes. Abbreviations: Ac: acetyl; acac: acetylacetone; AQN: anthraquinone; Ar: aryl; Atm: atmosphere; BINAM: 1,1′-binaphthalenyl-2,2′-diamine; BINAP: 2,2′- bis(diphenylphosphanyl)-1,1′-binaphthyl; BINEPINE: phenylbinaphthophosphepine; BINOL: 1,1′-bi-2-naphthol; Bmim: 1-butyl-3-methylimidazolium; Bn: benzyl; Boc: tert-butoxycarbonyl; Box: bisoxazoline; BSA: bis(trimethylsilyl)acetamide; Bu: butyl; Bz: benzoyl; c: cyclo; CBS: Corey-Bakshi-Shibata; Cbz: benzyloxycarbonyl; COD: cyclooctadiene; COE: cyclooctene; Cy: cyclohexyl; Dba: (E,E)-dibenzylideneacetone; DBU: 1,8-diazabicyclo[5.4.0]undec-7-ene; DCC: N,N′-dicyclohexylcarbodiimide; de: diastereomeric excess; DEAD: diethyl azodicarboxylate; Dec: decanyl; DHQD: dihydroquinidine; Difluorphos: 5,5′-bis(diphenylphosphino)-2,2,2′, 2′-tetrafluoro-4,4′-bi-1,3-benzodioxole; DIPEA: diisopropylethylamine: DKR: dynamic kinetic resolution; DMAP: 4-dimethylaminopyridine; DMSO: dimethyl sulfoxide; DNA: deoxyribonucleic acid; DOSP: N-(dodecylbenzenesulfonyl)prolinate; DTBM: di-tert-butylmethoxy; ee: enantiomeric excess; Et: ethyl; equiv.: equivalent; Fu: furyl; Hex: hexyl; HIV: human immunodeficiency virus; HMDS: hexamethyldisilazide; KR: kinetic resolution; L: ligand; LDA: lithium diisopropylamide; MAO: methylaluminoxane; Me: methyl; Ms: mesyl; MTBE: methyl tert-butyl ether; Naph: naphthyl; nbd: norbornadiene; NBS: N-bromosuccinimide; NIS: N-iodosuccinimide; Pent: pentyl; Ph: phenyl; Piv: pivaloyl; PMB: p-methoxybenzoyl; Pr: propyl Py: pyridyl; r.t.: room temperature; s: selectivity factor; Segphos: 5,5′- bis(diphenylphosphino)-4,4′-bi-1,3-benzodioxole; (S,S′,R,R′)- Tangphos: (1S,1S′,2R,2R′)-1,1′-di-tert-butyl-(2,2′)- diphospholane; TBS: tert-butyldimethylsilyl; TBDPS: tert-butyldiphenylsilyl; TCCA: trichloroisocyanuric acid; TEA: triethylamine; TEMPO: tetramethylpentahydropyridine oxide; THF: tetrahydrofuran; Thio: thiophene; Tf: trifluoromethanesulfonyl; TMS: trimethylsilyl; Tol: tolyl; Ts: 4-toluenesulfonyl (tosyl). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Reddy G.N.M.,CNRS Institute of Molecular Sciences of Marseilles | Caldarelli S.,CNRS Institute of Molecular Sciences of Marseilles
Chemical Communications | Year: 2011

The spectroscopic determination of phenolic molecules by means of multiple-quantum (MQ) NMR is demonstrated. Several classes of molecules (simple phenols, flavonols, secoiridoids and lignans) were unambiguously characterized in one pot analysis in an extract of extra virgin olive oil (EVOO). © 2011 The Royal Society of Chemistry.

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