Relay Annulation of Ammonium Ylides with Oxindole-Derived α,β-Unsaturated Ketimines: Catalytic Construction of Spiro-polycyclic Oxindoles

Organic Letters, Journal Year: 2024, Volume and Issue: 26(24), P. 5115 - 5119

Published: June 11, 2024

An ammonium ylide-based relay annulation was disclosed, which uses DABCO as the catalyst and oxindole-derived α,β-unsaturated ketimines γ-bromo-crotonates starting materials. This method enables rapid assembly of a series structurally novel spiro-polycyclic oxindoles containing bicyclo[4.1.0]heptane moiety through simultaneous generation three new bonds two rings in one step under mild reaction conditions.

Language: Английский

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Biocatalytic Construction of Spiro-Oxazolidinones via Halohydrin Dehalogenase-Catalyzed Ring Expansion of Spiro-Epoxides

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(14), P. 10670 - 10678

Published: July 1, 2024

Spiro-oxazolidinones are highly valuable compounds in the fields of medicinal and organic chemistry; however, methods for synthesizing these have not been well established. Herein, we present a biocatalytic methodology construction spiro-oxazolidinones through halohydrin dehalogenase-catalyzed ring expansion spiro-epoxides. By performing screening protein engineering dehalogenases, both chiral racemic were synthesized 24–47% yields (90–98% ee) 69–98% yields, respectively. The method was also applied to efficient synthesis drug fenspiride at high substrate concentration 200 mM (44 g/L). In addition, chemo-enzymatic strategy proposed overcome limitation maximum 50% yield inherent kinetic resolution process. Moreover, large-scale representative transformations carried out provide additional evidence practicality applicability approach.

Language: Английский

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Enantioselective and Diastereodivergent Synthesis of Spiroindolenines via Chiral Phosphoric Acid-Catalyzed Cycloaddition

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(30), P. 11611 - 11619

Published: July 23, 2021

A diastereodivergent and enantioselective synthesis of chiral spirocyclohexyl-indolenines with four contiguous stereogenic centers is achieved by a phosphoric acid-catalyzed cycloaddition 2-susbtituted 3-indolylmethanols 1,3-dienecarbamates. Modular access to two different diastereoisomers high enantioselectivities was obtained careful choice reaction conditions. Their functional group manipulation provides an efficient enantioenriched spirocyclohexyl-indolines -oxindoles. The origins this stereocontrol have been identified using DFT calculations, which reveal unexpected mechanism compared our previous work dealing enecarbamates.

Language: Английский

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Applications of Oxone® in Organic Synthesis: An Emerging Green Reagent of Modern Era

ChemistrySelect, Journal Year: 2022, Volume and Issue: 7(23)

Published: June 17, 2022

Abstract Presently, the major cornerstone of research community is to develop green as well sustainable protocols involving inexpensive catalysts and/or reagents without usage hazardous solvents under globally friendlier conditions in order shelter both mankind and environment. Therefore, needless say, there always a supreme need surrogate older, costlier unsafe strategies with novel economically environmental benign ones. To this context, recent past, oxone® (triple salt), very cheap oxidizing agent having chemical formula 2KHSO 5 ⋅ KHSO 4 K 2 SO enwrapped unique characteristics like easy handling, non‐toxic, safe, eco‐friendly, non‐polluting, stable, nicely soluble water, addition its utility for large‐scale synthesis etc. Bearing importance versatile reagent mind, we envisioned update advances made direction. Consequently, particular review article, developments arena oxone chemistry covering from 2013 2020 have been revealed no report appeared literature after wonderful Chem. Rev. published by group Hussain 2013. Herein, comprehensive detail variety oxidative transformations along complete plausible mechanistic steps exposed. For sure, present would be helpful tool scientific not only working area organic but also researchers other branches science technologies well.

Language: Английский

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Coupling partner-dependent unsymmetrical C–H functionalization of N-phenoxyacetamides leading to sophisticated spirocyclic scaffolds

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(17), P. 4583 - 4590

Published: Jan. 1, 2022

In this paper, a coupling partner-dependent unsymmetrical C–H functionalization of N -phenoxyacetamides leading to the formation sophisticated spirocyclic scaffolds is presented.

Language: Английский

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