CDC Reactions of N‐Aryl Tetrahydroisoquinolines Using Catalytic Amounts of DDQ: CH Activation under Aerobic Conditions

Abstract

An oxidative cross‐dehydrogenative coupling (CDC) reaction for the formation of CC and CP bonds is disclosed using a catalytic amount of DDQ (10 mol %) under aerobic conditions (see scheme). This unprecedented environmentally benign strategy of using AIBN (10 mol %) and molecular oxygen to regenerate DDQ exhibits a larger substrate scope. For the first time, an efficient utility of 4‐hydroxycoumarins as pronucleophiles for CDC is presented.

Dehydrierende Kreuzkupplungen von C‐H‐Bindungen: vielseitige Verfahren zur Bildung von C‐C‐Bindungen

“…[89] Die Reaktion läuft in Gegenwart von 10 Mol-% DDQ und 10 Mol-% AIBN in einer Sauerstoffatmosphäre glatt ab. Die Autoren schlugen einen Mechanismus vor, der mit der Oxidation des Tetrahydroisochinolins mit DDQ beginnt.…”

Remodeling of Fumagillol: Discovery of an Oxygen-Directed Oxidative Mannich Reaction

“…Under the optimized conditions, oxidative couplings with N -methylpyrrole, diethyl phosphite, 10 cyclohexanone silyl enol ether, 11 phenylacetylene, 12 and methylenecyclopentane 11 produced products 5a – 9a , respectively.…”

Oxidative Coupling Reaction of 1,3-diarylpropenes with Propane-1,3-dione Derivatives Mediated by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone with Molecular Oxygen

“…But there have been few reports of the oxidation promoted by a catalytic amount of DDQ with molecular oxygen as co-oxidant. [15][16][17][18][19][20][21] For example, Prabhu has developed the coupling reaction of N-aryltetrahydroisoquinoline using catalytic amount of DDQ and azobisisobutyronitrile (AIBN) with molecular oxygen. 17 Our group has studied the alkylation of 1,3-diarylpropene catalysed by DDQ/N-hydroxyphthalimide at the atmosphere of O 2 .…”

“…[15][16][17][18][19][20][21] For example, Prabhu has developed the coupling reaction of N-aryltetrahydroisoquinoline using catalytic amount of DDQ and azobisisobutyronitrile (AIBN) with molecular oxygen. 17 Our group has studied the alkylation of 1,3-diarylpropene catalysed by DDQ/N-hydroxyphthalimide at the atmosphere of O 2 . 20 We now report the coupling reaction between 1,3-diarylpropenes and active methylenic compounds mediated by a catalytic amount of DDQ with AIBN as an additive in the presence of O 2 .…”