ABSTRACT
The first total syntheses of (±)-catellatolactams A and B, two novel ansamacrolactams, are described in 5 and 8 steps, respectively. The strategy relies on an amidation reaction to couple the acylated Meldrum's acid and an aryl amine, a regioselective C-H insertion to construct the γ-lactam moiety, and an RCM reaction to forge the macrocycles with E-olefin. This concise and scalable synthesis provided over 200 mg of the target molecules.
ABSTRACT
The skeleton of lucidumone was constructed through oxidative dearomatization/intramolecular Diels-Alder reaction, Cu-mediated remote C-H hydroxylation, allyl oxidation, acid-promoted dynamic kinetic resolution cyclization, and benzylic oxidation.
Subject(s)
Skeleton , Cyclization , Cycloaddition Reaction , Molecular Structure , Oxidation-ReductionABSTRACT
The first total synthesis of Gardneria oxindole alkaloid (-)-gardmultimine A has been achieved in 19 steps from d-tryptophan in a fully stereocontrolled manner. This synthesis features (1) an Ir-catalyzed regioselective C-H borylation/oxidation sequence to introduce the C12 methoxyl group, (2) a stereocontrolled oxidative rearrangement of indole to construct the spirooxindole motif, and (3) an Au(I)-catalyzed transannular Conia-ene-type 6-exo-dig cyclization to establish the azabicyclo[2.2.2]octane skeleton and the exocyclic E-alkene with exclusive stereoselectivity.
Subject(s)
Tryptophan/chemistry , Catalysis , Cyclization , Molecular Structure , Oxidation-ReductionABSTRACT
A strategy for the synthesis of cis-hydrocarbazole with a C3 quaternary carbon center has been developed through nickel/Lewis acid dual-catalyzed arylcyanation. A wide array of cis-hydrocarbazoles was accessed with high diastereoselectivities and atom economies in a good yield. The rich chemistry of the installed nitrile group was demonstrated in the preparation of tryptamine- and tryptophol-derived cis-hydrocarbazoles.
