Ni-Catalyzed Homoallylation of Polyhydroxy N,O-Acetals with Conjugated Dienes Promoted by Triethylborane

Abstract

Abstract:In the presence of Ni-catalyst and triethylborane, N,O-acetals prepared from glycolaldehyde and glyceraldehyde with primary amines in situ underwent homoallylation with conjugated dienes to provide 2-amino-5-hexenols in high regio-and stereoselectivity. Under similar reaction conditions, N,O-acetals from carbohydrates with primary amines provided the corresponding polyhydroxy-bishomoallylamines in good to reasonable yields.

Intermolecular Metal-Catalyzed Reductive Coupling of Dienes, Allenes, and Enynes with Carbonyl Compounds and Imines

“…Using triethylborane as terminal reductant, the authors later extended this process to encompass imines derived from lactols. 86 As reported by Singh in 2015, exposure of p -anisidine to aryl aldehydes bearing ortho -carboxy substituents enables tandem nickel(0)-catalyzed diene-imine reductive coupling-lactam formation to form isoindolinones and isoquinolinones (Scheme 5). 87 For related 3component couplings of dienes, imines and organozinc reagents, the reader is referred to the review literature.…”

“…Coupling occurs predominantly at the diene C1 position to provide the products with good to complete levels of 1,3- syn -diastereoselectivity. Using triethylborane as terminal reductant, the authors later extended this process to encompass imines derived from lactols . As reported by Singh and co-workers in 2015, exposure of p -anisidine to aryl aldehydes bearing o -carboxy substituents enables tandem nickel(0)-catalyzed diene–imine reductive coupling–lactam formation to form isoindolinones and isoquinolinones (Scheme ).…”