The Experts below are selected from a list of 43776 Experts worldwide ranked by ideXlab platform
David Hochberg - One of the best experts on this subject based on the ideXlab platform.
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competitive exclusion principle in ecology and absolute Asymmetric Synthesis in chemistry
Chirality, 2015Co-Authors: Josep M. Ribó, David HochbergAbstract:The key concepts underlying the Frank model (1953) for spontaneous Asymmetric Synthesis in chemistry are traced back to the pioneering works of Volterra (1926) and Lotka (1932) on biological species competition. The Lotka-Volterra (L-V) two-species exclusive competition model reduces to the Frank model for the special case of distinguishable but degenerate species (i.e., the enantiomers). The important ecological principle of competitive exclusion, originally derived from the L-V two-competitors model, is a consequence of sufficiently antagonistic interactions between the species competing for limited common resources, or mutual inhibition, as the term is known in the chemical literature on absolute Asymmetric Synthesis. The L-V and Frank models are described by the same general differential equations, nevertheless a crucial thermodynamic distinction between these models is necessary to correlate ecological selection and chemical selectivity arising from 1) the absence of reversibility in biological transformations, in marked contrast to chemical reactions, and 2) the constraints in chemical scenarios on the reaction rate constants required to fulfill the principle of micro-reversibility. Chirality 27:722–727, 2015. © 2015 Wiley Periodicals, Inc.
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competitive exclusion principle in ecology and absolute Asymmetric Synthesis in chemistry
Chirality, 2015Co-Authors: Josep M. Ribó, David HochbergAbstract:The key concepts underlying the Frank model (1953) for spontaneous Asymmetric Synthesis in chemistry are traced back to the pioneering works of Volterra (1926) and Lotka (1932) on biological species competition. The Lotka-Volterra (L-V) two-species exclusive competition model reduces to the Frank model for the special case of distinguishable but degenerate species (i.e., the enantiomers). The important ecological principle of competitive exclusion, originally derived from the L-V two-competitors model, is a consequence of sufficiently antagonistic interactions between the species competing for limited common resources, or mutual inhibition, as the term is known in the chemical literature on absolute Asymmetric Synthesis. The L-V and Frank models are described by the same general differential equations, nevertheless a crucial thermodynamic distinction between these models is necessary to correlate ecological selection and chemical selectivity arising from 1) the absence of reversibility in biological transformations, in marked contrast to chemical reactions, and 2) the constraints in chemical scenarios on the reaction rate constants required to fulfill the principle of micro-reversibility.
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absolute Asymmetric Synthesis in enantioselective autocatalytic reaction networks theoretical games speculations on chemical evolution and perhaps a synthetic option
Chemistry: A European Journal, 2014Co-Authors: Josep M. Ribó, David Hochberg, Celia Blanco, Joaquim Crusats, Zoubir Elhachemi, Albert MoyanoAbstract:The Soai reaction and the Viedma deracemization of racemic conglomerate crystal mixtures are experimental pieces of evidence of the ability of enantioselective autocatalytic coupled networks to yield absolute Asymmetric Synthesis. Thermodynamically open systems or systems with non-uniform energy distributions may lead to chiral final states and, in systems able to come into thermodynamic equilibrium with their surroundings, to kinetically controlled absolute Asymmetric Synthesis. The understanding of network parameters and of the thermodynamic scenarios that may lead to spontaneous mirror symmetry breaking (SMSB) could assist in the development of new methods for Asymmetric Synthesis and enantioselective polymerizations (e.g., replicators), and to frame reasonable speculations on the origin of biological homochirality.
Josep M. Ribó - One of the best experts on this subject based on the ideXlab platform.
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competitive exclusion principle in ecology and absolute Asymmetric Synthesis in chemistry
Chirality, 2015Co-Authors: Josep M. Ribó, David HochbergAbstract:The key concepts underlying the Frank model (1953) for spontaneous Asymmetric Synthesis in chemistry are traced back to the pioneering works of Volterra (1926) and Lotka (1932) on biological species competition. The Lotka-Volterra (L-V) two-species exclusive competition model reduces to the Frank model for the special case of distinguishable but degenerate species (i.e., the enantiomers). The important ecological principle of competitive exclusion, originally derived from the L-V two-competitors model, is a consequence of sufficiently antagonistic interactions between the species competing for limited common resources, or mutual inhibition, as the term is known in the chemical literature on absolute Asymmetric Synthesis. The L-V and Frank models are described by the same general differential equations, nevertheless a crucial thermodynamic distinction between these models is necessary to correlate ecological selection and chemical selectivity arising from 1) the absence of reversibility in biological transformations, in marked contrast to chemical reactions, and 2) the constraints in chemical scenarios on the reaction rate constants required to fulfill the principle of micro-reversibility. Chirality 27:722–727, 2015. © 2015 Wiley Periodicals, Inc.
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competitive exclusion principle in ecology and absolute Asymmetric Synthesis in chemistry
Chirality, 2015Co-Authors: Josep M. Ribó, David HochbergAbstract:The key concepts underlying the Frank model (1953) for spontaneous Asymmetric Synthesis in chemistry are traced back to the pioneering works of Volterra (1926) and Lotka (1932) on biological species competition. The Lotka-Volterra (L-V) two-species exclusive competition model reduces to the Frank model for the special case of distinguishable but degenerate species (i.e., the enantiomers). The important ecological principle of competitive exclusion, originally derived from the L-V two-competitors model, is a consequence of sufficiently antagonistic interactions between the species competing for limited common resources, or mutual inhibition, as the term is known in the chemical literature on absolute Asymmetric Synthesis. The L-V and Frank models are described by the same general differential equations, nevertheless a crucial thermodynamic distinction between these models is necessary to correlate ecological selection and chemical selectivity arising from 1) the absence of reversibility in biological transformations, in marked contrast to chemical reactions, and 2) the constraints in chemical scenarios on the reaction rate constants required to fulfill the principle of micro-reversibility.
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absolute Asymmetric Synthesis in enantioselective autocatalytic reaction networks theoretical games speculations on chemical evolution and perhaps a synthetic option
Chemistry: A European Journal, 2014Co-Authors: Josep M. Ribó, David Hochberg, Celia Blanco, Joaquim Crusats, Zoubir Elhachemi, Albert MoyanoAbstract:The Soai reaction and the Viedma deracemization of racemic conglomerate crystal mixtures are experimental pieces of evidence of the ability of enantioselective autocatalytic coupled networks to yield absolute Asymmetric Synthesis. Thermodynamically open systems or systems with non-uniform energy distributions may lead to chiral final states and, in systems able to come into thermodynamic equilibrium with their surroundings, to kinetically controlled absolute Asymmetric Synthesis. The understanding of network parameters and of the thermodynamic scenarios that may lead to spontaneous mirror symmetry breaking (SMSB) could assist in the development of new methods for Asymmetric Synthesis and enantioselective polymerizations (e.g., replicators), and to frame reasonable speculations on the origin of biological homochirality.
Dieter Enders - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric Synthesis of pyrazoles and pyrazolones employing the reactivity of pyrazolin-5-one derivatives
Chemical Communications, 2015Co-Authors: Pankaj Chauhan, Suruchi Mahajan, Dieter EndersAbstract:Due to the frequent occurrence of the pyrazole core in many important naturally occurring and synthetic molecules, tremendous efforts have been made for their Synthesis. The pyrazolin-5-one derivatives have emerged as the most effective substrates for the Synthesis of useful pyrazoles and their corresponding pyrazolone derivatives. Recently, the reactivity of pyrazolin-5-ones has been used for the Asymmetric Synthesis of highly functionalised pyrazole and pyrazolone derivatives by employing organo- and metal-catalysts. This feature article focuses on the progress in the catalytic Asymmetric Synthesis of pyrazoles and pyrazolones using pyrazolin-5-one derivatives.
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Asymmetric Synthesis of fully substituted cyclopentane oxindoles through an organocatalytic triple michael domino reaction
ChemInform, 2015Co-Authors: Arne R Philipps, Gerhard Raabe, Dieter EndersAbstract:An efficient, highly stereoselective Asymmetric Synthesis of fully functionalized cyclopentanes bearing an oxindole moiety and several other functional groups in one pot is developed.
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Asymmetric Synthesis of functionalized3 4 dihydronaphthalenes via an organocatalytic dominonitroalkane michael aldol condensation reaction
Synlett, 2009Co-Authors: Dieter Enders, Chuan Wang, Jan W BatsAbstract:An organocatalytic domino nitroalkane-Michael addition/aldol condensation reaction has been developed. This process provides an efficient Asymmetric Synthesis of trisubstituted 3,4-dihydronaphthalenes in moderate to good yields (40―75%) and high stereoselectivities (de >98%, ee = 91 to >99%).
Benjamin List - One of the best experts on this subject based on the ideXlab platform.
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disulfonimide catalyzed Asymmetric Synthesis of δ amino β keto esters
Synlett, 2015Co-Authors: Qinggang Wang, Benjamin ListAbstract:A chiral disulfonimide-catalyzed Asymmetric Synthesis of δ-amino-β-keto esters via a vinylogous Mukaiyama–Mannich reaction of the Chan diene with N-Boc imines has been developed. The desired products were obtained in good to excellent yields and enantioselectivities.
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direct catalytic Asymmetric Synthesis of cyclic aminals from aldehydes
Journal of the American Chemical Society, 2008Co-Authors: Xu Cheng, Sreekumar Vellalath, Richard Goddard, Benjamin ListAbstract:A highly enantioselective Bronsted acid catalyzed direct Synthesis of cyclic aminals from aldehydes has been developed. The methodology has been applied to the first Asymmetric Synthesis of several antihypertensive aminal drugs including (R)-Thiabutazide.
Jan W Bats - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric Synthesis of functionalized3 4 dihydronaphthalenes via an organocatalytic dominonitroalkane michael aldol condensation reaction
Synlett, 2009Co-Authors: Dieter Enders, Chuan Wang, Jan W BatsAbstract:An organocatalytic domino nitroalkane-Michael addition/aldol condensation reaction has been developed. This process provides an efficient Asymmetric Synthesis of trisubstituted 3,4-dihydronaphthalenes in moderate to good yields (40―75%) and high stereoselectivities (de >98%, ee = 91 to >99%).