Synthesis of Complex Hexacyclic Compounds via a Tandem Rh(II)-Catalyzed Double-Cyclopropanation/Cope Rearrangement/Diels–Alder Reaction
نویسندگان
چکیده
Treatment of (E)-1-(methoxymethylene)-1,2,3,4-tetrahydronaphthalene with styryl diazoacetates in the presence of catalytic amounts of the dirhodium complex Rh2(S-DOSP)4 provides a highly enantioenriched hexacyclic product with 10 new stereogenic centers. The transformation proceeds by a cascade sequence starting with a double cyclopropanation of a benzene ring, followed by a Cope rearrangement of a divinylcyclopropane and then an intramolecular Diels-Alder cycloaddition.
منابع مشابه
Rhodium(II)-catalyzed intramolecular formal [4 + 3] cycloadditions of dienyltriazoles: rapid access to fused 2,5-dihydroazepines.
Rhodium(II)-catalyzed intramolecular [4 + 3] cycloadditions of dienyltriazoles have been developed, which enable the efficient synthesis of various fused 2,5-dihydroazepines. Mechanistically, the titled reaction proceeds via an interesting tandem cyclopropanation/aza-cope rearrangement.
متن کاملStereoselective Synthesis of Quinolizidine Alkaloids: (–)-Lasubin II
Initially, lasubin II was synthesized diastereoselectively in racemic form [3]. Asymmetric syntheses of lasubin II were achieved based on stereoselective transformations of enantiomerically pure substrates [4] or, for example, via a diastereoselective aza-Diels-Alder reaction using a resolved chiral arylaldehyde tricarbonylchromium complex [5]. Recently, an enantioselectively catalyzed aza-Diel...
متن کاملDFT Study on the Possible Intramolecular Rearrangement of Four Monocyclic Monoterpenes
As the basis and preliminary work of future experimental study on PAHs formation under high temperature, theoretical computations on the intramolecular rearrangement reactions of sylvestrene (1-methyl-3-vinylcyclohexene) and 1,4-dimethyl-4-vinylcyclohexene are conducted and reveal that they may be transformed to themselves. The conversion between Dipentene and 2,4-dimethyl-4-vinylcyclohexen...
متن کاملMolecular complexity via C-H activation: a dehydrogenative Diels-Alder reaction.
Traditionally, C-H oxidation reactions install oxidized functionality onto a preformed molecular skeleton, resulting in a local molecular change. The use of C-H activation chemistry to construct complex molecular scaffolds is a new area with tremendous potential in synthesis. We report a Pd(II)/bis-sulfoxide-catalyzed dehydrogenative Diels-Alder reaction that converts simple terminal olefins in...
متن کاملDiastereoselective synthesis of bridged polycyclic alkaloids via tandem acylation/intramolecular Diels-Alder reaction.
A mild and efficient stereoselective synthesis of hexacyclic indole alkaloids with a tetrahydro-β-carboline motif has been developed by utilizing the Pictet-Spengler reaction and tandem N-acylation followed by intramolecular Diels-Alder cyclization. Initially, a diene unit was installed in the tetrahedron β-carboline skeleton through Pictet-Spengler cyclization of the corresponding aldehyde wit...
متن کامل