Heterobicyclic Alkenes Research Articles

Rhodium-catalyzed ring-opening reactions of heterobicyclic akenes with heteroarene nucleophiles: an experimental and computational investigation

We present an experimental and computational investigation into the rhodium-catalyzed ring-opening reactions of heterobicyclic alkenes with heteroarene nucleophiles. The reaction provides a facile route to trans-substituted dihydronaphthalen-1-ol and 1-amino-dihydronaphthalene products in up to a 95% yield as a single diastereomer. This reaction is 100% atom-economic and offers C–C bond formation without prior functionalization of the coupling partners. The mechanism and origins of selectivity were probed with density functional theory (DFT) at the MN15/Def2-TZVPP level of theory. The energetic barriers between iridium- and rhodium-catalyzed pathways were compared via DFT. Additionally, the reactivity and energetic barriers across diverse heterobicyclic alkenes and heteroarenes were calculated to unveil their relative reactivity.

Iridium/nickel dual catalyzed hydroacylation of hetero-bicyclic alkenes under visible-light irradiation

Hetero-bicyclic alkenes are versatile synthetic motifs for the synthesis of highly substituted ring systems.

Rhodium-catalyzed ring-opening reactions of heterobicyclic alkenes with heteroarene nucleophiles

We present a rhodium-catalysed ring-opening reaction of heterobicyclic alkenes with indole and pyrrole nucleophiles, resulting in 1,2-disubstitued trans-dihydronaphthalene cores in up to a 95% yield as a single diastereomer. The Rh-catalysed reaction demonstrated tolerance for a broad scope of nucleophiles as well as various heterobicyclic alkenes. Notably, the reaction was successful with substrates that previously performed poorly or failed under iridium catalysis. This reaction is 100% atom-economic and offers C–C bond formation without prior functionalization of the coupling partners.

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes.

This review presents a comprehensive overview of transition-metal-catalyzed domino reactions of strained bicyclic alkenes, including both homo- and heterobicyclic alkenes. These compounds are important synthons in organic synthesis, providing an important platform for the construction of biologically/medicinally significant compounds which bear multiple stereocenters. The review has been divided according to the metal used in the reaction. An overview of the substrate scope, reaction conditions, and their potential applications in organic synthesis is discussed. A comprehensive outlook on the reactivity paradigms of homo- and heterobicyclic alkenes is discussed and should shed light on future directions for further development in this field.

Cobalt-catalyzed highly diastereoselective [3 + 2] carboannulation reactions: facile access to substituted indane derivatives

Cobalt(ii)-catalyzed oxidative annulation of hydrazones with heterobicyclic alkenes has been accomplished for accessing functionalized indane derivatives under aerobic conditions.

Copper-Catalyzed Cycloaddition of Heterobicyclic Alkenes with Diaryl Disulfides to Synthesize Dihydrobenzo[b]thiophene Derivatives.

A novel copper-catalyzed cycloaddition of diaryl disulfides to heterobicyclic alkenes has been developed. The C-S and C-C bonds can be formed simultaneously on the C═C bond of the olefins via a single-step cycloaddition to afford a series of 2,3-dihydrobenzo[b]thiophene derivatives. This reaction exhibits excellent diastereoselectivity and relatively broad substrate scope. Various functional groups attached to the substrates are tolerated in this protocol to give the corresponding exo adducts in moderate yields.

Rhodium(III)-catalyzed asymmetric carboboration of heterobicyclic alkenes

Abstract The transition-metal-catalyzed carboboration of heterobicyclic alkenes has been already established, however, the asymmetric version has never been uncovered. Herein, we describe a Rh(III)-catalyzed asymmetric carboboration of heterobicyclic alkenes, including 7-oxa- and 7-azabenzonorbornadienes, via borylative dimerization. During the transformation, another heterobicyclic alkene acts as electrophilic carbon reagent. The carboboration product bearing seven chiral centers could be efficiently obtained with good to high yields (70–98%) and excellent enantioselectivities (98−>99% ee). Moreover, several transformations of the carboboration product were also presented.

Chiral Cobalt(II) Complex Catalyzed Asymmetric [2,3]-Sigmatropic Rearrangement of Allylic Selenides with α-Diazo Pyrazoleamides

Organoselenium compounds, due to their high structural diversity, special function, and biological activities, have drawn attention in synthetic chemistry. Herein, a novel example of chiral N,N′-di...

Synthesis of Fused Spiropyrrolidine Oxindoles Through 1,3‐Dipolar Cycloaddition of Azomethine Ylides Prepared from Isatins and α‐Amino Acids with Heterobicyclic Alkenes

The synthesis of various fused spiropyrrolidine oxindoles from isatins, amino acids, and heterobicyclic alkenes through a 1,3‐dipolar cycloaddition is described. For the first time, we used heterobicyclic alkenes as a dipolarophile in 1,3‐dipolar cycloaddition of the azomethine ylide generated by decarboxylation. Triflic acid mediated aromatization of cycloaddition products has been demonstrated. A possible mechanism is proposed that the formation of iminium carboxylate intermediate (I), azomethine ylide intermediate (II) via decarboxylation, subsequent 1,3‐dipolar cycloaddition with oxabenzonorbornadiene to give cycloaddition product.

Rhodium-Catalyzed Enantioselective Hydroselenation of Heterobicyclic Alkenes.

A highly efficient Rh(I)/(S)-xyl-Binap catalytic system is developed for the asymmetric hydroselenation of various nonpolar olefins with diselenides. Under these mild reaction conditions, a wide range of heterobicyclic alkenes give selenol-incorporated adducts in excellent enantioselectivities (up to 97%) along with high yields (up to 96%) by overcoming self-promoted racemic hydroselenation. The strategy is also applied for kinetic resolution of unsymmetric oxabenzonorbornadiene.

Asymmetric Transfer Hydrogenation of Heterobicyclic Alkenes with Water as Hydrogen Source.

The asymmetric transfer hydrogenation of heterobicyclic alkenes was accomplished by using water as the sole hydrogen source. The transformation was co-catalyzed by Pd(OAc)2/Zn(OTf)2 dual catalyst with metallic zinc as reducing agent. Various azabenzonorbornadienes and oxabenzonorbornadienes were transformed to the corresponding chiral 1,2-dihydronaphthalenes by the asymmetric reductive ring-opening reactions with good to excellent enantioselectivities.

Asymmetric Hydrophosphination of Heterobicyclic Alkenes: Facile Access to Phosphine Ligands for Asymmetric Catalysis

Asymmetric hydrophosphination is the most atomically economical and straightforward approach to the construction of chiral organophosphorus compounds. Good stereoselectivities have been achieved in...

Desymmetrization of Achiral Heterobicyclic Alkenes through Catalytic Asymmetric Hydrophosphination.

Asymmetric addition of diarylphosphines to oxa- and azabicyclic alkenes proceeded in the presence of a chiral phosphapalladacycle catalyst and a mild acid at room temperature to give exclusively the enantioenriched addition products in excellent yields and good selectivities. Three new chiral carbon centers were generated stereoselectively by the catalytic hydrophosphination reaction.

RhIII-catalyzed annulation of N-methoxyindozamides with heterobicyclic alkenes towards indolo[3,2-c]heteroarenes

A rhodium-catalyzed annulation protocol towards indolo[3,2-c]-1-azaanthraenes and successive treatment with different acids, which offered diverse indolo[3,2-c]-heteroarenes, were herein demonstrated. The transition metal-mediated system offered a direct and facile approach towards the heterocyclic compounds of great significance, enjoying high efficiency and good functional groups compatibility.

Asymmetric Ring-Opening of Heterobicyclic Alkenes with Anilines

Asymmetric Ring-Opening of Heterobicyclic Alkenes with Anilines

Rhodium-Catalyzed Asymmetric Arylative Ring-Opening Reactions of Heterobicyclic Alkenes with Anilines

Asymmetric arylative ring-opening reactions of heterobicyclic alkenes with anilines have been reported for the first time. A wide range of heterobicyclic alkenes, including azabenzonorbornadienes and oxabenzonorbornadienes, were well tolerated in the reaction with various anilines, and they generally delivered the corresponding chiral aryltetralin derivatives in good to excellent enantioselectivities. The reaction is speculated to proceed through the Friedel-Crafts reaction pathway.

Cobalt-catalyzed asymmetric reactions of heterobicyclic alkenes with in situ generated organozinc halides

A general strategy for the asymmetric allylation and benzylation of heterobicyclic alkenes is described by employing in situ generated organozinc halides.

Cobalt‐Catalyzed Diastereoselective [4+2] Annulation of Phosphinamides with Heterobicyclic Alkenes at Room Temperature

AbstractCobalt‐catalyzed sp2 C−H bond functionalization of diarylphosphinamides with heterobicyclic alkenes was demonstrated at room temperature employing commercially available cobalt(II)‐salts. The effectiveness of this strategy was illustrated with the reaction of various 8‐aminoquinoline derived phosphinic amides and 7‐oxa/azabenzonorbornadienes. The reaction conditions exhibited excellent functional group tolerance and high diastereoselectivities. Furthermore, extension of this approach to the preparation of polyaryl cyclic phosphinamides was achieved through the dehydrative ring opening/aromatization sequence.magnified image

Rhodium(III)‐Catalyzed Annulation of N‐Methoxybenzamides with Heterobicyclic Alkenes by C–H Functionalization: Synthesis of Benzo[b]phenanthridinones

A protocol for the rhodium(III)‐catalyzed annulation of N‐methoxybenzamides with 7‐oxa/azabenzonorbornadienes by C–H activation was developed. This method allowed the synthesis of polycyclic products containing an oxygen/nitrogen‐bridged structure in excellent yields. The annulated products were successfully transformed into benzo[b]phenanthridinones by a ring‐opening/aromatization sequence.

ChemInform Abstract: Cobalt‐Catalyzed Allylation of Heterobicyclic Alkenes: Ligand‐Induced Divergent Reactivities.

AbstractAn unprecedented formal hydroallylation of heterobicyclic alkenes is achieved upon treatment with allyltrifluoroborate (II) in the presence of CoBr2 as the catalyst.