title: Catalytic enantioselective allylation of dienals through the intermediacy of unsaturated pi-allyl complexes.
abstract: The nickel-catalyzed enantioselective addition of allylboronic acid pinacol ester [allylB(pin)] to alpha,beta,gamma,delta-unsaturated aldehydes is described. This reaction results in a remarkable inversion of substrate olefin geometry, providing the Z,E-configured reaction product in good enantioselectivity and olefin stereoselectivity. The reaction appears to proceed by conversion of the dienal to an unsaturated pi-allyl complex followed by reductive elimination via transition state II. Enantioselectivities range from 73-94% ee for a range of delta-substituted dienals when chiral ligand L3 is employed.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: James P
authors.initials: JP
authors.lastname: Morken
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D009532:Nickel / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D000447:Aldehydes; D000475:Alkenes; D009532:Nickel
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