Stereoselective Synthesis of Oxabicyclo[2.2.1]heptenes via a Tandem Dirhodium(II)-Catalyzed Triazole Denitrogenation and [3 + 2] Cycloaddition

A novel synthetic strategy for the diastereoselective synthesis of structurally diverse oxabicyclo[2.2.1]­heptenes has been developed, featuring a tandem reaction combining a Rh-catalyzed triazole denitrogenation and a novel type of [3 + 2] cycloaddition reaction. This tandem reaction was thought to proceed via a five-membered oxonium ylide intermediate, which was formed by the intramolecular nucleophilic attack of the carbonyl group on the α-imino metallocarbene followed by an inter- or intramolecular [3 + 2] dipolar cycloaddition with a range of alkynes and alkenes

Stereoselective Synthesis of Oxabicyclo[2.2.1]heptenes via a Tandem Dirhodium(II)-Catalyzed Triazole Denitrogenation and [3 + 2] Cycloaddition

A novel synthetic strategy for the diastereoselective synthesis of structurally diverse oxabicyclo[2.2.1]­heptenes has been developed, featuring a tandem reaction combining a Rh-catalyzed triazole denitrogenation and a novel type of [3 + 2] cycloaddition reaction. This tandem reaction was thought to proceed via a five-membered oxonium ylide intermediate, which was formed by the intramolecular nucleophilic attack of the carbonyl group on the α-imino metallocarbene followed by an inter- or intramolecular [3 + 2] dipolar cycloaddition with a range of alkynes and alkenes

Stereoselective Synthesis of Oxabicyclo[2.2.1]heptenes via a Tandem Dirhodium(II)-Catalyzed Triazole Denitrogenation and [3 + 2] Cycloaddition

A novel synthetic strategy for the diastereoselective synthesis of structurally diverse oxabicyclo[2.2.1]­heptenes has been developed, featuring a tandem reaction combining a Rh-catalyzed triazole denitrogenation and a novel type of [3 + 2] cycloaddition reaction. This tandem reaction was thought to proceed via a five-membered oxonium ylide intermediate, which was formed by the intramolecular nucleophilic attack of the carbonyl group on the α-imino metallocarbene followed by an inter- or intramolecular [3 + 2] dipolar cycloaddition with a range of alkynes and alkenes

Stereoselective Synthesis of Oxabicyclo[2.2.1]heptenes via a Tandem Dirhodium(II)-Catalyzed Triazole Denitrogenation and [3 + 2] Cycloaddition

A novel synthetic strategy for the diastereoselective synthesis of structurally diverse oxabicyclo[2.2.1]­heptenes has been developed, featuring a tandem reaction combining a Rh-catalyzed triazole denitrogenation and a novel type of [3 + 2] cycloaddition reaction. This tandem reaction was thought to proceed via a five-membered oxonium ylide intermediate, which was formed by the intramolecular nucleophilic attack of the carbonyl group on the α-imino metallocarbene followed by an inter- or intramolecular [3 + 2] dipolar cycloaddition with a range of alkynes and alkenes

Formal Total Synthesis of (±)-Lycojaponicumin C

The formal total synthesis of (±)-lycojaponicumin C has been accomplished. Key transformations include a Rh-catalyzed formal [3 + 2] cycloaddition reaction to construct the bicyclic [3.3.0] scaffold bearing two vicinal quaternary carbon centers, a stereoselective γ-hydroxyl directed Michael addition to introduce the vinyl group at a bulky position, and a late-stage ring-closing metathesis reaction to form the cyclohexanone ring

Tunable and Chemoselective Syntheses of Dihydro­iso­benzo­furans and Indanones via Rhodium-Catalyzed Tandem Reactions of 2‑Triazole-benzaldehydes and 2‑Triazole-alkylaryl Ketones

Two novel rhodium­(II)-catalyzed tandem reactions were developed for the synthesis of dihydro­isobenzo­furan and indanone derivatives from 2-triazole-benzalde­hydes and 2-triazole-alkylaryl ketones. Dihydro­isobenzo­furan derivatives were obtained in good yields with high regioselectivities when alcohols were used as nuclophiles in these reactions, whereas the replacement of the alcohol with water resulted in the diastereoselective formation of highly functionalized indanone derivatives

Asymmetric Total Synthesis of (−)-Guignardones A and B

The asymmetric total synthesis of (−)-guignardones A (2) and B (1) has been accomplished. The highly oxidized 6-oxabicyclo[3.2.1]­octane core was constructed from d-quinic acid via substitution/desulfurization reaction with thiophenol to forge the bridged ring scaffold, and a Pummerer rearrangement and 1,4-addition/elimination sequence was employed to install the β-carbonyl group at the congested C-1 position. A late-stage Knoevenagel condensation–6π-electrocyclization and directed hydrogenation formed (−)-guignardone B (1), which was subjected to dehydration to furnish (−)-guignardone A (2)

Formal Total Synthesis of Hybocarpone Enabled by Visible-Light-Promoted Benzannulation

The formal total synthesis of hybocarpone was achieved in eight steps from commercially available 1,2,4-trimethoxybenzene. Key transformations include a visible-light-promoted benzannulation to construct the key α-naphthol intermediate and a modified CAN-mediated dimerization/hydration cascade sequence to generate the vicinal all-carbon quaternary centers in a stereocontrolled manner. The total synthesis of boryquinone was also achieved in seven steps

Palladium-Catalyzed Oxidative Rearrangement of Tertiary Allylic Alcohols to Enones with Oxygen in Aqueous Solvent

A one-pot procedure for Pd­(TFA)₂-catalyzed 1,3-isomerization of tertiary allylic alcohols to secondary allylic alcohols followed by a Pd­(TFA)₂/neocuproine-catalyzed oxidative reaction to β-disubstituted-α,β-unsaturated kenones was developed

Synthetic Study toward the Total Synthesis of Maoecrystal V

A novel and concise approach for the construction of the core structure of maoecrystal V (1) has been developed. Utilizing the lead-mediated arylation of β-ketoesters and oxidative dearomatization/IMDA reaction as key steps, the two consecutive all-carbon quaternary centers (C-9 and C-10) were constructed in a stereoselective manner. The developed chemistry paves the way for the total synthesis of this fascinating natural product