Palladium(II)-Catalyzed Michael-Type Hydroarylation of Nitroalkenes Using Aryltins and Sodium Tetraarylborates

A variety of aryltin compounds and sodium tetraarylborates can be employed for Michael-type hydroarylation reactions of nitroalkenes to afford (beta)-arylnitroalkanes in moderate to good yields in the presence of either LiCl, MgCl2, or CaCl2 and a catalytic amount of palladium(II) salt (0.05 molar amount) in acetic acid. Results show that 50-70% of aryl groups out of all in these aryl compounds can be transferred to the products in this hydroarylation. The addition of a catalytic amount (0.05-0.10 molar amount) of a Lewis acid chloride, BiCl3 or SbCl3, much improves the product yield in some cases.