Dehydrogenative Oxidation of Cyclic Amines on a Diruthenium Complex

作者：Shimogawa Ryuichi; Fujita Ryosuke; Takao Toshiro; Suzuki Hiroharu

来源：Organometallics, 2017, 36(10): 1893-1896.

DOI：10.1021/acs.organomet.7b00231

The dehydrogenative oxidation of cyclic amines catalyzed by a diruthenium complex and mechanistic studies are described. Cyclic amines and water reacted in the presence of Cp double dagger Ru(mu-H)(4)RuCp double dagger (1) (Cp double dagger = 1,2,4-tri-tert-butylcyclopentadienyl) to afford lactams accompanied by elimination of the hydrogen gas. The reaction of hexamethylenimine with 1 at 160 degrees C afforded Cp double dagger Ru(mu-H)(2)(mu-C6H11N)RuCp double dagger (2), having a novel mu-cyclic imine ligand through N-H and C-H bond cleavages. Further C-H bond cleavage of 2 proceeded at 180 degrees C to afford Cp double dagger Ru(mu-H)(mu-eta(2):eta(2)-C6H10N)RuCp double dagger (4), having a perpendicularly coordinated imidoyl ligand. Complex 4 readily reacted with water and liberated epsilon-caprolactam. The cooperative interaction of the two ruthenium atoms leading to N-H and double C-H bond cleavages was the key to the dehydrogenative oxidation of cyclic amines.

• 出版日期2017-5-22