Abstract:
Methods and compositions are provided for the direct catalytic asymmetric aldol reaction of aldehydes with donor molecules selected from ketones and nitroalkyl compounds. The reactions employ as catalyst a Group 2A or Group 2B metal complex of a ligand of formula (I), as defined further herein.
Abstract:
The preparation of aromatic ketones substituted with a thioether group at the ortho position is accomplished by the initial reaction of an aromatic nucleus substituted with a halide and an ortho nitro group with a nitroalkane in the presence of a hydroxide base. The resulting ortho-nitroalkyl nitroarene compound is converted to the corresponding ortho-nitroaryl ketone by an oxidative Nef reaction. The aromatic nitro group of the ortho-nitroaryl ketone is replaced with a thioether group by reaction with a thiolate anion, most preferably under phase-transfer conditions. Aromatic ketones may be used to prepare various pharmaceutical and herbicidal compounds.