β-Carboline directed regioselective hydroxylation by employing Cu(OAc)2 and mechanistic investigation by ESI-MS

A β-carboline directed regioselective C-H activation protocol for hydroxylation has been developed by employing Cu(OAc)2, a cost-effective 3d metal. This fastidious reaction proceeds under microwave irradiation and furnishes exclusively ortho-hydroxylated products with moderate to good yields under greener reaction conditions. Gratifyingly, this approach retains considerable functional group tolerance and is feasible on both electron-rich and electron-deficient substrates. This protocol signifies monohydroxylation on β-carboline via C-H functionalization which leads into development of biologically relevant molecules. The reaction mechanism was confirmed by intercepting and characterizing all the proposed intermediates by ESI-QTOF-MS.

Ru(II)-Catalyzed Regioselective Hydroxymethylation of β-Carbolines and Isoquinolines via C-H Functionalization: Probing the Mechanism by Online ESI-MS/MS Screening

A Ru(II)-catalyzed regioselective C-H activation toward hydroxymethylation of β-carbolines and isoquinolines as effective directing groups has been developed, and the mechanism was probed by using online electrospray ionization-tandem mass spectrometry. The introduction of the hydroxymethyl group in the biologically relevant molecules routed via C-H functionalization remains an important task. Gratifyingly, this protocol draws attention to the regioselective formation of monohydroxymethylated β-carboline/isoquinoline products exclusively.