Chiral Brønsted Acid-Catalyzed Intramolecular Asymmetric Dearomatization Reaction of Indoles with Cyclobutanones via Cascade Friedel–Crafts/Semipinacol Rearrangement

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(37), P. 25878 - 25887

Published: Sept. 3, 2024

The highly efficient synthesis of chiral indolines fused with an azabicyclo[2.2.1]heptanone moiety is achieved by asymmetric dearomatization reaction indoles cyclobutanones. A new imidodiphosphorimidate (IDPi) catalyst synthesized and exhibits extraordinary activity in promoting a cascade Friedel-Crafts/semipinacol rearrangement. Target molecules are prepared good yields (up to 95%) excellent enantioselectivity 98% ee) operational convenience. Combined experimental computational studies provide detailed mechanistic insights into the energy landscape origin stereochemical induction reaction.

Language: Английский

---

Anion Recognition-Directed Supramolecular Catalysis with Functional Macrocycles and Molecular Cages

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 25, 2024

ConspectusThe development of supramolecular chemistry has provided a variety host molecules and noncovalent tools for boosting catalytic processes, stimulating the emergence advance catalysis, among which macrocyclic cage-like compounds have attracted great attention due to their possession an enzyme-mimetic cavity recognition ability. While privileged scaffolds such as crown ethers, cyclodextrins, cucurbiturils, calixarenes, metal-coordinated cages been widely used, skeletons usually do not contain directional binding site; activation mainly rely on cation-associated interactions or hydrophobic effects. In this context, recent anion drawn our developing recognition-directed approach by using tailor-made functionalized macrocycles cages. Anions are important existing species in both biological chemical systems play role regulating structure function enzymes. We envisioned that taking advantage anions, including rich variety, diverse geometry, multiple interaction sites, sophisticated cooperation can be manipulated confined directing efficient selective catalysis.Following concept, we initiated study introducing typical thiourea H-bonding groups design synthesize series bis-thiourea macrocycles, especially chiral incorporating linkers. Taking obtained strong, cooperative binding, macrocycle-enabled counteranion trapping strategy was developed, afforded greatly enhanced efficiency excellent stereocontrol acid-catalyzing reactions. Furthermore, inspired sulfate-induced dimerization assembly, built substrate-induced assembly system, enabling induced-fit network enantioselective catalysis. addition, recognition-driven chirality gearing with more trithiourea cage revealed, could provide basis implementing anion-triggered allosteric catalysis within induced helical space. Not limited hydrogen bonding, emerging anion-π were largely exploited. A triazine-based prism containing three V-shaped electron-deficient π-cavities constructed, properties studied. Based established driving highly paved way push toward practical useful catalyst design.These results demonstrated anion-recognition direction serve powerful, versatile It is feasible only employing exogenous anions (e.g., counteranion) handle but also regulation anionic active intermediates/transition states, from use conventional recognition.

Language: Английский

---

Recent Advancement on Selectfluor Mediated Synthesis of Heterocyclic Molecules

The Chemical Record, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 16, 2025

Abstract Selectfluor, [1‐chloromethyl‐4‐fluoro‐1,4‐diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)], is a highly valuable reagent in contemporary chemistry, serving not only as an electrophilic fluorinating agent but also effective catalyst the synthesis of various pharmaceutically relevant heterocycles. This review article seeks to present comprehensive overview significant heterocyclic ring formations facilitated by selectfluor. Both metal‐free and metal‐catalyzed recent advancement on selectfluor mediated cyclisation processes are discussed this mainly over last eight years (2017‐April 2024).

Language: Английский

---

Controlling Stereoselectivity with Noncovalent Interactions in Chiral Phosphoric Acid Organocatalysis

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

Chiral phosphoric acids (CPAs) have emerged as highly effective Brønsted acid catalysts in an expanding range of asymmetric transformations, often through novel multifunctional substrate activation modes. Versatile and broadly appealing, these benefit from modular tunable structures, compatibility with additives. Given the unique types noncovalent interactions (NCIs) that can be established between CPAs various reactants─such hydrogen bonding, aromatic interactions, van der Waals forces─it is unsurprising catalyst systems become a promising approach for accessing diverse chiral product outcomes. This review aims to provide in-depth exploration mechanisms by which impart stereoselectivity, positioning NCIs central feature connects broad spectrum catalytic reactions. Spanning literature 2004 2024, it covers nucleophilic additions, radical atroposelective bond formations, highlighting applicability CPA organocatalysis. Special emphasis placed on structural mechanistic features govern CPA-substrate well tools techniques developed enhance our understanding their behavior. In addition emphasizing details stereocontrolling elements individual reactions, we carefully structured this natural progression specifics broader, class-level perspective. Overall, findings underscore critical role catalysis significant contributions advancing synthesis.

Language: Английский

---

Macrocyclic Catalysis Mediated by Water: Opportunities and Challenges

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 2, 2024

This work summarizes macrocyclic catalysis strategies for overcoming aqueous-phase reactivity challenges, product inhibition, and catalyst compatibility in “one-pot” reactions.

Language: Английский

---

1.4 Recent Developments in Enantioselective Fluorination

Published: Jan. 1, 2024

Abstract This review describes the main advances in enantioselective fluorination over last decade, while also recalling early developments this area. Three strategies have been employed to achieve concomitant introduction of a fluorine atom by C(sp3)—F bond formation with stereocon-trol at same carbon center: (1) use chiral fluorinating agents, (2) diverse organocatalytic approaches, and (3) transition-metal-catalyzed fluorinations. These complementary ap-ply both electrophilic nucleophilic

Language: Английский

---