Significant progress has been observed in recent years in the synthesis of allylic amines which are important building blocks in synthetic chemistry. Most of these processes are effective towards the preparation of allylic amines with limited potential to introduce three or four different substituents on the olefinic unit in a stereocontrolled fashion. Therefore, the discovery of a mild and operationally simple protocol allowing such challenging stereoselective synthesis of multi-substituted allylic amines remains an inspiring target. Herein, we report the first general and practical methodology for the stereoselective synthesis of tri- and tetra-substituted allylic amines based on Pd-catalyzed conversion of allyl surrogates readily obtained from cyclic vinyl carbonates. These rare conversions are characterized by excellent stereoselectivity, operational simplicity, mild reaction conditions and wide scope in reaction partners. DFT studies were performed to rationalize the stereocontrol in these allylic amine formation reactions, and evidence is provided that the formation of a six-membered palladacyclic intermediate leads towards the formation of (Z)- configured allylic amine products.
Stereoselective and Versatile Preparation of Tri- and Tetra-Substituted Allylic Amine Scaffolds under Mild Conditions
J. Am. Chem. Soc. 2016, 138, 11970-11978.