ABSTRACT
A new palladium(II) catalyzed methodology for the direct synthesis of alkylidene isoindolinones from N-alkoxybenzamides is presented. Isoindolinone formation proceeds through a highly efficient and E-selective C-H activation/Heck/Aza-Wacker sequence. Substoichiometric amounts of benzoquinone can be employed in a cooperative oxidation system with O(2), leading to facile purification of products. Modification of the reaction conditions provides a general route to substituted phthalimides by carbonylation with CO. Both systems were found to tolerate a wide range of functionality.
Subject(s)
Benzamides/chemistry , Palladium/chemistry , Carbon/chemistry , Catalysis , Hydrogen/chemistry , Molecular StructureABSTRACT
N-Ts and N-Boc derivatives of 1,2-diamines and 1,2-amino alcohols are shown to undergo efficient Pd(II)-catalyzed aza-Wacker reactions with a large range of electron-deficient alkenes. The resulting enamine intermediate generally undergoes cyclization with the second heteroatom to form 1,3-heterocycles. The sequence facilitates the rapid synthesis of saturated oxazolidines, imidazolidines, and their derivatives. Use of N-L-valinol derivatives results in highly diastereoselective reactions, where the net stereochemical outcome diverges between N-Ts and N-Boc.