Direct Bis-Arylation of Cyclobutanecarboxamide via Double C–H Activation: An Auxiliary-Aided Diastereoselective Pd-Catalyzed Access to Trisubstituted Cyclobutane Scaffolds Having Three Contiguous Stereocenters and an All-<i>cis</i> Stereochemistry
An auxiliary-aided Pd-catalyzed highly diastereoselective double C–Hactivation and direct bis-arylation of methylene C(sp3)–H bonds of cyclobutanecarboxamides and the syntheses of several novel trisubstituted cyclobutanecarboxamide scaffolds having an all-cis stereochemistry are reported. Extensive screening of various auxiliaries and reaction conditions was performed to firmly establish the optimized