Synthesis of polysubstituted spiroazepines via [4 + 3] annulation reaction of ninhydrin-derived Morita−Baylis−Hillman carbonates with 1‑heterodienes

Journal of Molecular Structure, Journal Year: 2025, Volume and Issue: unknown, P. 141478 - 141478

Published: Jan. 1, 2025

Language: Английский

---

Lewis Base Controlled (4 + 3) and (4 + 2) Annulations of MBH Carbonates with Benzofuran‐derived Azadienes: Access to Highly Substituted Benzofuro[3,2‐b]azepines and Spirotetrahydroquinolines

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(21), P. 4521 - 4527

Published: Aug. 7, 2024

Abstract Catalyst‐controlled switchable (4+3) and (4+2) annulation reactions of Morita–Baylis–Hillman carbonates with benzofuran‐derived azadienes have been established. Employing PCy 3 as the catalyst, reaction could provide a variety synthetically useful benzofuro[3,2‐ b ]azepines in good yields (80–92%) excellent chemo‐ regioselectivities via cycloaddition reactions. Whereas changing catalyst from to DMAP, were switched construct highly substituted spirotetrahydroquinoline scaffolds three sequential stereocenters containing all‐carbon spiro‐quaternary efficiency diastereoselectivities (92–96% all cases>25:1 dr ) annulations. In addition, synthetic utility this method was further showcased by gram‐scale transformations product.

Language: Английский

---

DABCO-catalyzed mono- and bisallylation of β,γ-unsaturated ketones with Morita-Baylis-Hillman carbonates

New Journal of Chemistry, Journal Year: 2024, Volume and Issue: 48(35), P. 15446 - 15451

Published: Jan. 1, 2024

Mono- and bisallylation of β,γ-unsaturated ketones with MBH carbonates in the presence DABCO at rt, offered α-2-alkoxycarbonyl, α,α-di(2-alkoxycarbonyl) α,γ-di(2-alkoxycarbonyl) α,β-unsaturated moderate to excellent yields.

Language: Английский

---

Substrate-controlled chemoselective assembly of coumarins and Morita–Baylis–Hillman alcohols from salicylaldehydes with acrylates

Synthetic Communications, Journal Year: 2024, Volume and Issue: 54(18), P. 1579 - 1588

Published: Aug. 27, 2024

Substrate-controlled divergent reactions of between salicylaldehydes and acrylates have been developed. By using methyl acrylate as the substrate with salicylaldehydes, a domino reaction was established, delivering coumarins good yield (up to 81% yields) high chemoselectivity under mild conditions. Whereas changed tert-butyl or iso-propyl acrylate, classical Morita − Baylis Hillman adducts were produced in yields 75% near exclusivity otherwise identical conditions, without any other competitive products. Additionally, synthetic utility present methodology further demonstrated by transformation. The structure typical product unambiguously established single crystal X-ray diffraction analysis.

Language: Английский

---

Benzenediazonium Tetrafluoroborate‐Catalyzed Formal [3 + 3] Cyclization of 4‐Hydroxycoumarins With Propargylicalcohols

Journal of Heterocyclic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 27, 2024

ABSTRACT A formal [3 + 3] cycloaddition of 4‐hydroxycoumarins with propargylicalcohols was established under mild conditions. This strategy utilizes diazonium tetrafluoroborate as the Lewis acid catalyst and provides a practical approach for delivering pyranocoumarin derivatives in moderate to high yield. The structure cycloadduct unequivocally confirmed by single‐crystal x‐ray diffraction. potential synthetic applications this were also highlighted scale‐up experiment further transformation.

Language: Английский

---