An unprecedented approach for the synthesis of imine derivatives was achieved via a Pd(II)-catalyzed dearomatization reaction of N-aryl ureas with internal alkynes. The corresponding spirocyclic imine derivatives were obtained with 20 examples in good to excellent yields. Mechanistic investigation indicated that an interesting 1,3-palladium migration process led to the α-regioselective dearomatization when 2-naphthyl ureas were used as the substrates. Fused ring products could also be obtained to further prove this migration process.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.orglett.6b00363 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
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 PDFChitosan-Based Schiff Bases (CSBs) and Their Metal Complexes: Promising Antimicrobial Agents.
Molecules
January 2025
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy.
The scientific interest in the chemical modification of chitosan to increase its solubility and application has led to its conjugation with Schiff bases, which are interesting scaffolds endowed with diverse biological properties. The resultant chitosan-based Schiff bases (CSBs) are widely studied in scientific literature due to the myriad of activities exerted, both catalytic and biological, including anticancer, anti-inflammatory, antioxidant, and especially antimicrobial ones. Antimicrobial resistance (AMR) is one of the major public health challenges of the twenty-first century because it represents a threat to the prevention and treatment of a growing number of bacterial, parasitic, viral, and fungal infections that are no longer treatable with the available drugs.
View Article and Find Full Text PDFEnantioselective Decarboxylative Mannich Reactions of α,β-Unsaturated β'-Ketoacids and Isatin Imines: Application in the Synthesis of Spiro[indoline-3,2'-piperidine]-2,4'-diones.
Org Lett
January 2025
Department of Chemistry, Memorial University, St. John's, Newfoundland and Labrador A1B 3X7, Canada.
Organocatalytic, enantioselective decarboxylative Mannich reactions of α,β-unsaturated β'-ketoacids and isatin -Boc imines, to give the corresponding 3-carbamoyl-2-oxindole derivatives, were developed. Subsequent N-deprotection and diastereoselective, intramolecular, aza-Michael reaction of the free amine provides previously unreported spiro[indoline-3,2'-piperidine]-2,4'-diones.
View Article and Find Full Text PDFα/β Conflicting Aromaticity Under the Microscope: Study of Pro-Aromatic Radicals.
Chemphyschem
January 2025
University of Vigo, Dept. of Physical Chemistry, Lagoas-Marcosende, 36310, Vigo, SPAIN.
The aromaticity of a representative sample of pro-aromatic radicals and its nitro, amino, hydroxyl and imine substituted derivatives has been analysed by means of multicentre delocalization indices (MCI) and nuclear-independent chemical shifts (NICS). Because of their radical character, these compounds may exhibit conflicting α/ß aromaticity, so that the contribution of α and β electrons to the MCI and NICS has been analysed separately and their values qualitatively interpreted in terms of the 2n+1/2n rule. All the monocyclic radicals investigated show conflicting α/β aromaticity.
View Article and Find Full Text PDFWant 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!