Possible method for conversion of harmaline into harmine

[downwardsfromzero]

I just stumbled across a research paper which details a fairly simple, copper-catalyzed oxidation of tetrahydrobetacarbolines with air at room temperature. The reaction was optimized with copper (II) bromide, DMSO as the solvent and the hindered base, DBU (1,8-diazabicyclo[5,4,0]undec-7-ene) - only this latter reagent might be harder to obtain. And maybe bromides aren't so easy to find. Whatever.

Also, it's rather the opposite of our usual goal of obtaining THH

Anyhow, here's the paper:

Cu-catalyzed mild and efficient oxidation of THβCs using air: application in practical total syntheses of perlolyrine and flazin

A mild, efficient and environmentally benign method for synthesis of aromatic β-carbolines via Cu()-catalyzed oxidation of 1,2,3,4-tetrahydro-β-carbolines (THβCs) was developed, in which air (O[2] ) was used as the clean oxidant. ...

www.ncbi.nlm.nih.gov

Abstract

A mild, efficient and environmentally benign method for synthesis of aromatic β-carbolines via Cu(ii)-catalyzed oxidation of 1,2,3,4-tetrahydro-β-carbolines (THβCs) was developed, in which air (O2) was used as the clean oxidant. This method has advantages such as environmentally friendliness, mildness, very good tolerance of functional groups, high yielding and easy experiment operation. In addition, this new methodology was successfully applied in the efficient and practical total syntheses of β-carboline alkaloids perlolyrine and flazin.

Will copper prove to be a useful catalyst for the hydrogenation of harmaline to THH though?