A Novel Palladium-Based Heterogeneous Catalyst for Tandem Annulation: A Strategy for Direct Synthesis of Acridones
作者:Darío C. Gerbino、H. Sebastián Steingruber、Pamela Mendioroz、M. Julia Castro、María A. Volpe
DOI:10.1055/s-0042-1751371
日期:2023.2
In order to develop an efficient, rapid, and modular cascade strategy for the direct synthesis of acridones, palladium supported on sulfated alumina and microwave activation are employed. Multifunctional heterogeneous palladium catalysts were prepared in order to carry out the sequential annulation via a Buchwald–Hartwig amination followed by an intramolecular annulation in a one-pot process. This
isolated from traditional African herbal medicine Cryptolepis sanguinolenta, and its broad spectrum of biological activities has been illuminated in past decades. In this study, neocryptolepine and its derivatives (1-49) were designed and synthesized from economical and readily available starting materials. Their structures were confirmed by protonnuclearmagneticresonance, carbon nuclearmagnetic resonance
Chemodivergent Spirocyclization of 2‐Sec‐Aminobenzilidene Imidazolones: Lewis Versus Brønsted Acids Catalysis
作者:Dmitrii S. Ivanov、Elvira R. Zaitseva、Alexander Yu. Smirnov、Dina A. Rustamova、Andrey A. Mikhaylov、Maria A. Sycheva、Darya A. Gluschenko、Nadezhda S. Baleeva、Mikhail S. Baranov
DOI:10.1002/adsc.202200109
日期:2022.4.26
Benzylidene imidazolones with ortho- secondary aminogroup undergo acid-promoted chemodivergent spirocyclization. Strong Lewisacids provide access to spirocyclic tetrahydroquinolines via [1,5]-hydride shift triggered cyclization despite of the presence of free secondary amino group. Brønstedacids promote unprecedented intramolecular umpolung hydroamination reaction with the formation of spirocyclic indolines