title: Asymmetric additive-free aryl addition to aldehydes using perhydrobenzoxazines as ligands and boroxins as aryl source.
abstract: A highly efficient enantioselective aryl addition to aldehydes using boroxins as aryl source and conformationally restricted perhydro-1,3-benzoxazines as ligands is reported. Both enantiomeric forms of chiral arylphenylmethanols and 1,1'-disubstituted diarylmethanols are afforded with excellent yields and enantioselectivities using the same ligand by means of an appropriate combination of boroxin and aromatic aldehyde. The enantiocontrol is not significantly influenced by electronic effects or steric hindrance, even with substituted boroxins. Very homogeneous ee's are reached when substituted arylboroxins are employed, without the use of any class of additive or pre-treatment.
authors.affiliation: Instituto CINQUIMA and Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, Dr Mergelinas/n, 47011 Valladolid, Spain.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Infante
authors.forename: Javier
authors.initials: J
authors.lastname: Nieto
authors.forename: Celia
authors.initials: C
authors.lastname: Andrés
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D048588:Benzoxazines / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry*; D008024:Ligands; D000432:Methanol / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D048588:Benzoxazines; D001896:Boron Compounds; D006573:Heterocyclic Compounds, 1-Ring; D008024:Ligands; D000432:Methanol