Ruthenium-Porphyrin-Catalyzed [4 + 2] Cycloaddition of α,β-Unsaturated Imines and Aldehydes.

Org Lett

Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.

Published: November 2015

A new efficient synthetic route to unsymmetrically substituted dihydropyridine scaffolds via dehydrative [4 + 2] cycloaddition of N-tosylated α,β-unsaturated imines with aldehydes has been developed. This transformation is enabled by (i) the remarkable catalytic ability of the cationic Ru(IV) porphyrin complex to activate both the imino and carbonyl groups and (ii) the hydrophobic nature of the porphyrin ligand, which helps realize robust Lewis acidity in the dehydrative cycloaddition.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.5b02654DOI Listing

Publication Analysis

Top Keywords

αβ-unsaturated imines
8
imines aldehydes
8
dehydrative cycloaddition
8
ruthenium-porphyrin-catalyzed cycloaddition
4
cycloaddition αβ-unsaturated
4
aldehydes efficient
4
efficient synthetic
4
synthetic route
4
route unsymmetrically
4
unsymmetrically substituted
4

Similar Publications

We report on the synthesis and characterization of an imine-type nickel complex produced the complexation of an generated 2-(iminomethyl)phenol ligand with Ni ion. The use of this complex as an electrocatalyst for H evolution in a DMF solution, with acetic acid as the proton source, was investigated in detail, employing both experimental analyses (electrochemical analysis, spectroscopy analysis) and theoretical analysis (plateau current analysis). The overpotential required for H evolution is about 590 mV with a faradaic efficiency of 49% after 3 hours bulk electrolysis, competing with the two-electron reduction of free-imine groups in the ligand.

View Article and Find Full Text PDF

Imine Synthesis by Engineered d-Amino Acid Oxidase from Porcine Kidney.

ACS Omega

January 2025

Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.

Various symmetric and asymmetric imines were synthesized using the novel amine oxidase, obtained as variants of d-amino acid oxidase (pkDAO) from porcine kidney (Y228L/R283G) and (I230A/R283G). Active primary imines produced as intermediates in the oxidation of methylbenzylamine (MBA) derivatives were trapped by aliphatic, aromatic amines and diamines as nucleophiles forming new imines. ()-Fluoro-MBA was the best substrate for symmetric imine synthesis, providing almost stoichiometric conversion (100 mM) and achieving nearly 100% yield.

View Article and Find Full Text PDF

Exploring the dual roles of sec-dependent effectors from Candidatus Liberibacter asiaticus in immunity of citrus plants.

Plant Cell Rep

January 2025

MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China.

The three SDEs of CLas were expressed in citrus leaves by AuNPs-PEI mediated transient expression system, and promoted the proliferation of CLas and inhibited citrus immunity. Huanglongbing (HLB) is the most severe bacterial disease of citrus caused by Candidatus Liberibacter asiaticus (CLas). CLas suppress host immune responses and promote infection by sec-dependent effectors (SDEs), thus insight into HLB pathogenesis is urgently needed to develop effective management strategies.

View Article and Find Full Text PDF

Synthesis of Alkyl α-Amino-benzylphosphinates by the Aza-Pudovik Reaction; The Preparation of the Butyl Phenyl--phosphinate Starting P-Reagent.

Molecules

January 2025

Department of Organic Chemistry and Technology, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3, 1111 Budapest, Hungary.

Butyl phenyl--phosphinate that is not available commercially was prepared from phenyl--phosphinic acid by three methods: by alkylating esterification (i), by microwave-assisted direct esterification (ii), and unexpectedly, by thermal esterification (iii). Considering the green aspects, selectivity and scalability, the thermal variation seemed to be optimal. However, there was need for prolonged heating.

View Article and Find Full Text PDF

-Halogenation and -Alkoxylation of Phenylglycine Derivatives by Pd-Mediated C-H Functionalization: Scope and Limitations.

Molecules

January 2025

Instituto de Síntesis Química y Catálisis Homogénea, ISQCH (CSIC-Universidad de Zaragoza), Pedro Cerbuna 12, 50009 Zaragoza, Spain.

Orthopalladated derivatives from substituted phenylglycines [Pd(μ-Cl)(CHRC(R)(R)N(R)] () react with halogenating reagents (PhICl, Br, I) () to give the corresponding o-halogenated amino acids CH(X)RC(R)(R)N(R) (). The reaction is general and tolerates a variety of functional groups (R to R) at the aryl ring, the Cα, and the N atom. On the other hand, the reaction of [Pd(μ-Cl)(CHRC(R)(R)N(R)] () with PhI(OAc) in the presence of a variety of alcohols ROH () gives the o-alkoxylated phenylglycines CH(OR)RC(R)(R)N(R) (), also as a general process.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!