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Imine Substrates (imine + substrate)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Allylation of Aldehyde and Imine Substrates with In Situ Generated Allylboronates , A Simple Route to Enatioenriched Homoallyl Alcohols

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2005
Sara Sebelius
Abstract Allylation of aldehyde and imine substrates was achieved using easily available allylacetates and diboronate reagents in the presence of catalytic amounts of palladium. This operationally simple one-pot reaction has a broad synthetic scope, as many functionalities including, acetate, carbethoxy, amido and nitro groups are tolerated. The allylation reactions proceed with excellent regio- and stereoselectivity affording the branched allylic isomer. By employment of commercially available chiral diboronates enantioenriched homoallyl alcohols (up to 53,% ee) could be obtained. The mechanistic studies revealed that the in situ generated allylboronates react directly with the aldehyde substrates, however the allylation of the sulfonylimine substrate requires palladium catalysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Copper-Catalyzed One-Pot Synthesis of 2-Alkylidene-1,2,3,4- tetrahydropyrimidines

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009
Wei Lu
Abstract A one-pot synthesis of N -sulfonyl-2-alkylidene-1,2,3,4-tetrahydropyrimidines via a highly selective and copper-catalyzed multicomponent reaction of sulfonyl azides, terminal alkynes and ,,,-unsaturated imines has been developed. The ,,,-unsaturated imine substrates could be generated from amines and ,,,-unsaturated aldehydes in a one-pot process. The procedure is concise, general and efficient. [source]

Enantioselective Trifunctional Organocatalysts for Rate- Enhanced Aza-Morita,Baylis,Hillman Reactions at Room Temperature

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009
Jean-Marc Garnier
Abstract A Brønsted acid-activated trifunctional organocatalyst, based on the BINAP scaffold, was used for the first time to catalyze aza-Morita-Baylis,Hillman reactions between N -tosylimines and methyl vinyl ketone with fast reaction rates and good enantioselectivity at room temperature. This trifunctional catalyst, containing a Lewis base, a Brønsted base, and a Brønsted acid, required acid activation to confer its enantioselectivity and rate improvement for both electron-rich and electron-deficient imine substrates. The role of the amino Lewis base of 1a was investigated and found to be the activity switch in response to an acid additive. The counterion of the acid additive was found to influence not only the excess ratio but also the sense of asymmetric induction. [source]