- Synthesis of cis bis-β-lactams via Staudinger cycloaddition reaction using C2-symmetric 1,2-diamines
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An efficient stereoselective synthesis of bis-β-lactams via cycloaddition reaction (Staudinger reaction) of ketenes with bisimines derived from C2-symmetric 1, 2-diamines is described. The reaction provided diastereomeric mixture of meso and C2-symmetric cis-bis-β- lactams with higher selectivity for meso-bis-β-lactams.
- Shaikh, Aarif L.,Puranik, Vedavati G.,Deshmukh
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p. 2441 - 2451
(2007/10/03)
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- Modular ligands for asymmetric synthesis: Enantioselective catalytic CuII-mediated condensation reaction of ethyl pyruvate with Danishefsky's diene
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Only the correct order of addition of the components is required to prepare a variety of chiral Lewis acids. The complexes (for example, 4) formed by the condensation of chiral, nonracemic 1,2-diamines with ketones and subsequent addition of Cu(OTf)2
- Dalko, Peter I.,Moisan, Lionel,Cossy, Janine
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p. 625 - 628
(2007/10/03)
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- METALLATION OF BENZYLIDENEBENZYLAMINE
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The reactions of benzylidenebenzylamine with methyllithium and lithium diethylamide were investigated by GLC.Products with different structures from condensation of the azomethine are formed: Cyclic 2,4,5-triphenyl-3-benzylimidazolidine and noncyclic dibenzylidene-1,2-diphenylethylenediamine.Investigation of the effects of the solvent, temperature, and ratio of reagents on the reaction made it possible to obtain conditions for synthetic application of the 1,3-diphenylazaallyllithium, obtained by metallation of benzylidenebenzylamine, in reactions with alkyl halides, carbon dioxide, carbonyl compounds, and phenyl isocyanate.These conditions involve a temperature between -60 and -70 deg C and an equimolar ratio between the reagents.
- Gracheva, R. A.,Potapov, V. M.,Sivov, N. A.,Sivova, L. I.
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p. 1963 - 1970
(2007/10/02)
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