Encapsulating Ru Nanoclusters for Reductive Imination of Biomass-Based Furfural by Shape-Selective Catalysis

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(3), P. 2017 - 2032

Published: Jan. 21, 2025

Reductive imination of aldehydes to the corresponding secondary imines, while attractive and promising, remains a big challenge due consecutive hydrogenation hydroammonolysis in situ formed imine. Herein, we describe strategy shape-selective catalysis for reductive biomass-derived furfural with H2NOH H2 by using Ru nanoclusters confined within regular micropores ZSM-5 (Ru@ZSM-5). The Ru@ZSM-5 features oxime-hydrogenation furfurylimine-hydrogenation their closed molecular sizes pore apertures (5.3 × 5.6 Å) ZSM-5. In contrast, imine (4.3 11.2 large size could not pass through reach active sites, thus remaining unaffected without further hydroammonolysis. shape-selectivity is confirmed catalyst-passivation hydrogen-spillover experiments. shows high activity good recyclability easily extended variety aldehydes.

Language: Английский

---

Bifunctional iminophosphorane catalysed enantioselective sulfa-Michael addition of alkyl thiols to alkenyl benzimidazoles

Chemical Science, Journal Year: 2018, Volume and Issue: 9(34), P. 6969 - 6974

Published: Jan. 1, 2018

The first enantioselective sulfa-Michael addition of alkyl thiols to alkenyl benzimidazoles, enabled by a bifunctional iminophosphorane (BIMP) organocatalyst, is described.

Language: Английский

---

Activating Pronucleophiles with High pK_a Values: Chiral Organo‐Superbases

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(21), P. 8004 - 8014

Published: Dec. 2, 2019

Abstract Direct deprotonation represents an extremely simple, straightforward, and atom‐economic strategy to activate pronucleophiles bearing acidic proton. However, the difficulty often arises in activating with high p K a values by using conventional chiral tertiary amines. To overcome this challenge, handful of novel Brønsted superbases, including amidines, guanidines, cyclopropenimines, iminophosphoranes, have been discovered recent years. This minireview focuses on application these organo‐superbases catalytic asymmetric reactions weakly pronucleophiles, highlights their comparison amines, demonstrating highly efficient processes stereoselectivity controlled conversions superbases. The advantage new superbases brings great opportunity for developing more transformations pronucleophiles.

Language: Английский

---

Phosphorus‐Containing Superbases: Recent Progress in the Chemistry of Electron‐Abundant Phosphines and Phosphazenes

Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 27(42), P. 10807 - 10825

Published: May 25, 2021

The renaissance of Brønsted superbases is primarily based on their pronounced capacity for a large variety chemical transformations under mild reaction conditions. Four major set screws are available the selective tuning basicity: nature basic center (N, P, …), degree electron donation by substituents to central atom, possibility charge delocalization, and energy gain hydrogen bonding. Within past decades, plethora neutral electron-rich phosphine phosphazene bases have appeared in literature. Their outstanding properties advantages over inorganic or charged now made them indispensable as auxiliary deprotonation processes. Herein, an update chemistry phosphines phosphazenes given. In addition, due widespread interest, use catalysis ligands coordination highlighted.

Language: Английский

---

Epoxides: Small Rings to Play with under Asymmetric Organocatalysis

ACS Organic & Inorganic Au, Journal Year: 2022, Volume and Issue: 2(4), P. 289 - 305

Published: March 29, 2022

Optically pure epoxides are recognized as highly valuable products and key intermediates, useful in different areas from pharmaceutical agrochemical industries to natural product synthesis materials science. The predictable fate of the ring-opening process, terms stereoselectivity often regioselectivity, enables functional groups be installed at vicinal carbon atoms a desired manner. In this way, widespread utility either for synthetic applications or final can obtained. advent asymmetric organocatalysis provided new convenient tool, not only their preparation but also elaboration class heterocycles. review, we focus on recent developments stereoselective organocatalytic reactions meso-epoxides, kinetic resolution racemic epoxides, Meinwald-type rearrangement. Examples processes toward specific targets, which include ring opening an epoxide intermediate, illustrated.

Language: Английский

---

Metal-free photosensitized aminosulfonylation of alkenes: a practical approach to β-amido sulfones

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(10), P. 3857 - 3863

Published: Jan. 1, 2023

A general and environmentally friendly organic photo-induced strategy was developed for the synthesis of diverse alkyl-substituted β-amino sulfone derivatives, including primary, secondary, tertiary products.

Language: Английский

---

Diversity‐Orientated Stereoselective Synthesis through Pd‐Catalyzed Switchable Decarboxylative C−N/C−S Bond Formation in Allylic Surrogates

Chemistry - A European Journal, Journal Year: 2018, Volume and Issue: 24(72), P. 19156 - 19161

Published: Oct. 25, 2018

Switchable catalytic transformation of reactants can be a powerful approach towards diversity-orientated synthesis from easily available molecular synthons. Herein, an endogenous ligand-controlled, Pd-catalyzed allylic substitution allowing for either selective C-N or C-S bond formation using vinylethylene carbonates (VECs) and N-sulfonylhydrazones as coupling partners has been developed. This versatile methodology provides facile, divergent route the highly chemo- stereoselective functional sulfones sulfonohydrazides. The newly developed protocol features wide substrate scope (nearly 80 examples), broad group tolerance, potential late-stage functionalization bioactive compounds. isolation crystallographic analysis catalytically competent π-allyl Pd complex suggests that pathway leading to products proceeds through different manifold previously proposed VECs with nucleophiles.

Language: Английский

---

Asymmetric Synthesis of N‐Fused 1,3‐Oxazolidines via Pd‐Catalyzed Decarboxylative (3+2) Cycloaddition

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(9), P. 1836 - 1840

Published: March 10, 2020

Abstract Efficient synthesis of optically active N‐fused 1,3‐oxazolidines containing quaternary and tertiary stereocenters was achieved via Pd‐catalyzed asymmetric (3+2) cycloadditions sulfamate‐derived cyclic imines vinylethylene carbonates. Using a chiral phosphoramidite ligand, the proceeded effectively providing sulfamidate‐fused in high yields (up to 96%) with stereoselectivities 25:1 dr; >99% ee). Additionally, scale‐up reaction further transformations product were also demonstrating synthetic utility toward construction useful heterocycles such as oxazoline bearing stereocenter. magnified image

Language: Английский

---

Development of Molecular Transformations on the Basis of Catalytic Generation of Anionic Species by Organosuperbase

Bulletin of the Chemical Society of Japan, Journal Year: 2021, Volume and Issue: 94(1), P. 339 - 356

Published: Jan. 1, 2021

Abstract In this account, we summarized our recent efforts to develop molecular transformations under Brønsted base catalysis on the basis of own guiding principles for designing reaction systems, that include “the generation and application anionic species which are difficult utilize in conventional systems” employment organosuperbases possessing much higher basicities than organic bases as a catalyst”. particular, discussed reactions involving carbanions less acidic compounds through formal umpolung process from carbonyl [3+2] cycloadditions synthetic equivalent 1,3-dipole epoxide opening.

Language: Английский

---

Regio- and Stereoselective Intermolecular 1,2-Difunctionalization of Terminal Alkynes: An Approach to Access (Z)-β-Amidovinylsulfones

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 2873 - 2884

Published: Feb. 14, 2024

We have developed the first I2/base-catalyzed regio- and stereoselective intermolecular β-amidosulfonylation of terminal alkynes using sodium sulfinates quinoxalinone derivatives. The present methodology is compatible with a broad spectrum various heterocyclic amides, alkynes, sulfinates. It provides rapid access to valuable (Z)-β-amidovinyl sulfones at mild conditions. Moreover, synthetic application this was demonstrated by late-stage functionalization numerous bioactive molecules.

Language: Английский

---