Using a combination of Au nanoparticle‐catalyzed oxidation under an O2 atmosphere and a Ti‐doped montmorillonite (Ti‐MMT)‐catalyzed tandem arylation/double cyclization, we developed an original and highly selective method for the synthesis of ortho‐tetrahydrocannabinol derivatives from simple substrates. The reaction sequence could be performed in two steps in batch mode or in a single operation in continuous‐flow reactors. The abnormal regioselectivity was proposed to be the result of the non‐innocent role of the MMT support, TiIV cation coordination, and a Lewis acid‐assisted Brønsted acid (LBA) mechanism.

In the hunt for a simple, mild, and scalable protocol for gold nanoparticle‐catalyzed oxidation of benzylic and allylic alcohols under O2, we have used commercially available gold nanoparticles supported on alumina to selectively oxidize a large range of activated alcohols to the corresponding carbonyl compounds in good yields (68–99 %) and with excellent selectivity (ca. 100 %). The true heterogeneous nature of the catalysis by gold was demonstrated, allowing us to further adapt this protocol to continuous‐flow reactors by using the tube‐in‐tube technology, in which higher yields were obtained thanks to an improved oxygenation of the reaction medium.