- Novel multicomponent domino approach to 2,5-bifunctionalized five-membered cyclic nitrones
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Multicomponent reactions of 2,2-dimethylpenta-3,4-di-enal oxime with aldehydes and primary alcohols were studied and the optimum conditions for preparing a new family of 2,5-substituted five-membered cyclic nitrones were identified. This reaction offers direct access to the target structures in a single synthetic step. The scope and limitations of the reaction were evaluated, and all products were isolated and fully characterized. Georg Thieme Verlag Stuttgart · New York.
- Buchlovi, Marian,Man, Stanislav,Potaek, Milan
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scheme or table
p. 973 - 982
(2012/05/04)
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- Water as efficient medium for mild decarbonylation of tertiary aldehydes
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Decarbonylation of the tertiary aldehydes 4-ethyl-4-formyl-hexanenitrile (2) and 2-methyl-2-phenylpropanal (4) promoted by dioxygen occurs at room temperature only if suspended in water probably via the sequential acyl radical-CO liberation-tertiary radical that is promoted by an 'on water' process originating preferentially from the corresponding tertiary hydroperoxide.
- Rodrigues, Catarina A.B.,De Matos, Marta Norton,Guerreiro, Bruno M.H.,Gon?alves, Ana M.L.,Rom?o, Carlos C.,Afonso, Carlos A.M.
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supporting information; experimental part
p. 2803 - 2807
(2011/06/19)
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- Aza cope rearrangement of propargyl enammonium cations catalyzed by a self-assembled "nanozyme"
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The tetrahedral assembly [Ga4L6]12- [L = N,N-bis(2,3-dihydroxybenzoyl)-1,5-diaminonaphthalene) encapsulates a variety of cations, including propargyl enammonium cations capable of undergoing the aza Cope rearrangement. For propargyl enammonium substrates that are encapsulated in the [Ga4L6]12- assembly, rate accelerations by factors of up to 184 compared with the background reaction rate were observed. After rearrangement, the product iminium ion is released into solution and hydrolyzed, allowing for catalytic turnover. The activation parameters for the catalyzed and uncatalyzed reaction were determined, revealing that a decrease in the entropy of activation is responsible for the observed rate enhancements. The catalyzed reaction exhibits saturation kinetics: the rate data obeyed the Michaelis-Menten model of enzyme kinetics, and competitive inhibition using a nonreactive guest was demonstrated.
- Hastings, Courtney J.,Fiedler, Dorothea,Bergman, Robert G.,Raymond, Kenneth N.
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experimental part
p. 10977 - 10983
(2009/02/05)
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- Highly efficient [2 + 2] intramolecular cyclizations of allenynes under microwave irradiation: Construction of fused bicyclic compounds
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A palladium [2 + 2] cycloaddition of 1,6- and 1,7- allenyne carboxylates and microwave-mediated [2 + 2] cycloaddition of various 1,n-allenynes were developed and, particularly, the microwave irradiated [2 + 2] cycloaddition of allenynes can provide a simp
- Oh, Chang Ho,Gupta, Arun Kumar,Park, Dai In,Kim, Nakjoong
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p. 5670 - 5672
(2007/10/03)
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