Unexpected CC Bond Formation via Doubly Dehydrogenative Coupling of Two Saturated sp³ C−H Bonds Activated with a Polymolybdate

In this communication, we demonstrate that polyoxomolybdates can activate sp3 C−H bonds in aliphatic amines. Unexpectedly, a carbon−carbon double bond is formed from two aliphatic primary amines via the activation and dehydrogenative coupling of two sp3 C−H bonds near the nitrogen atom bearing a hexamolybdate. Detailed experiments including 1H NMR, 13C NMR, IR, UV−vis, ESI-MS, and especially X-ray single-crystal diffraction substantially confirm the existence of carbon−carbon double bonds in a class of so-resulting organic−inorganic hybrid molecules, which are made up of two terminally substituted imidohexamolybdate cages bridged by a trans-tetrasubstituted, conjugated, rigid ethylene system. This discovery perhaps opens an interesting road to elaborate the CC double bond directly via the functionalization of saturated C−H bonds.