scholarly journals Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

2019 ◽  
Vol 15 ◽  
pp. 2447-2457
Author(s):  
Gerardo M Ojeda ◽  
Prabhat Ranjan ◽  
Pavel Fedoseev ◽  
Lisandra Amable ◽  
Upendra K Sharma ◽  
...  
Keyword(s):  
Multicomponent Reaction ◽  
Catalytic Reaction ◽  
Molecular Diversity ◽  
Complex Compounds ◽  
Rhodium Catalyst ◽  
Metal Center ◽  
Hybrid Products ◽  
Directing Group ◽  
Efficient Sequence

An efficient sequence based on the Ugi-azide reaction and rhodium(III)-catalyzed intermolecular annulation has been established for the preparation of tetrazole-isoquinolone/pyridone hybrids. Several N-acylaminomethyltetrazoles were reacted with arylacetylenes to form the hybrid products in moderate to very good yields. The method relies on the capacity of the rhodium catalyst to promote C(sp2)–H activation in the presence of a suitable directing group. The Ugi-azide reaction provides broad molecular diversity and enables the introduction of the tetrazole moiety, which may further assist the catalytic reaction by coordinating the metal center. The scope of the isoquinolones is very wide and may be extended to the preparation of complex compounds having heterocyclic moieties such as pyridone, furan, thiophene and pyrrole, as well as the corresponding benzo-fused derivatives. The developed procedure is simple, reproducible and does not require inert conditions.

Microwave-Assisted Domino Cyclization Reactions

2021 ◽  
Vol 08 ◽  
Author(s):  
Yogesh B. Wagh ◽  
Dipak S. Dalal
Keyword(s):  
Microwave Irradiation ◽  
Molecular Diversity ◽  
Medicinal Chemistry ◽  
Complex Molecule ◽  
Complex Compounds ◽  
Synthetic Chemistry ◽  
Domino Reactions ◽  
Cyclization Reactions ◽  
Microwave Assisted ◽  
Synthetic Approaches

Background: Microwave-assisted domino cyclization reactions have attracted great interest for researchers to synthesize complex compounds in shorter times with increase yields. The domino reactions were used in various synthetic approaches and many drug deliveries in medicinal chemistry with microwave assisted approach. Methods: Microwave irradiation has been applied for the various domino reactions. The research related to microwave assisted domino cyclization was reviewed and the important methodologies are collected from 2011-2021. Results: Only those methodologies that involve microwave-assisted domino cyclization reactions during synthesis in a related manner have been reviewed. Along with some recent syntheses that are microwave-assisted regarding new heterocyclic moieties are summarized. Conclusion: Microwave-assisted domino cyclization reactions can be employed to quickly explore and increase molecular diversity in synthetic chemistry. We hope that this review will be helpful to find out complex molecule synthesis by microwave-assisted domino cyclization reactions. This review aimed to explain the applications of microwaves for the domino reactions from 2011-2021. In this respect, the microwave mediated methods help researchers to make helpful studies.

scholarly journals Molecular Diversity and Network Complexity in Growing Protocells

2019 ◽  
Author(s):  
Atsushi Kamimura ◽  
Kunihiko Kaneko
Keyword(s):  
Catalytic Reaction ◽  
Host Species ◽  
Molecular Diversity ◽  
Reaction Network ◽  
Cellular Growth ◽  
Cell Reproduction ◽  
A Cell ◽  
Molecular Components ◽  
Growth Scaling ◽  
Cellular Components

AbstractA great variety of molecular components is encapsulated in cells. Each of these components is replicated for cell reproduction. To address an essential role of the huge diversity of cellular components, we study a model of protocells that convert resources into catalysts with the aid of a catalytic reaction network. As the resources are limited, it is shown that diversity in intracellular components is increased to allow the use of diverse resources for cellular growth. Scaling relation is demonstrated between resource abundances and molecular diversity. We then study how the molecule species diversify and complex catalytic reaction networks develop through the evolutionary course. It is shown that molecule species first appear, at some generations, as parasitic ones that do not contribute to replication of other molecules. Later, the species turn to be host species that support the replication of other species. With this successive increase of host species, a complex joint network evolves. The present study sheds new light on the origin of molecular diversity and complex reaction network at the primitive stage of a cell.

scholarly journals Molecular Diversity and Network Complexity in Growing Protocells

Life ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 53
Author(s):  
Atsushi Kamimura ◽  
Kunihiko Kaneko
Keyword(s):  
Molecular Species ◽  
Catalytic Reaction ◽  
Molecular Diversity ◽  
Reaction Network ◽  
Cellular Growth ◽  
Reaction Networks ◽  
Cell Reproduction ◽  
A Cell ◽  
Molecular Components ◽  
Cellular Components

A great variety of molecular components is encapsulated in cells. Each of these components is replicated for cell reproduction. To address the essential role of the huge diversity of cellular components, we studied a model of protocells that convert resources into catalysts with the aid of a catalytic reaction network. As the resources were limited, the diversity in the intracellular components was found to be increased to allow the use of diverse resources for cellular growth. A scaling relation was demonstrated between resource abundances and molecular diversity. In the present study, we examined how the molecular species diversify and how complex catalytic reaction networks develop through an evolutionary course. At some generations, molecular species first appear as parasites that do not contribute to the replication of other molecules. Later, the species turn into host species that contribute to the replication of other species, with further diversification of molecular species. Thus, a complex joint network evolves with this successive increase in species. The present study sheds new light on the origin of molecular diversity and complex reaction networks at the primitive stage of a cell.

scholarly journals Protodepalladation as a Strategic Elementary Step in Catalysis

Synthesis ◽  
2018 ◽  
Vol 50 (24) ◽  
pp. 4699-4714 ◽  
Author(s):  
Keary Engle ◽  
Miriam O’Duill
Keyword(s):  
Oxidation State ◽  
Catalytic Reaction ◽  
Elementary Step ◽  
Metal Center ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid ◽  
Organic Products ◽  
New Applications ◽  
Catalytic Cycles

Protodepalladation is the redox-neutral conversion of a C–Pd(II) bond into a C–H bond via reaction with a Brønsted acid. It is the microscopic reverse of Pd(II)-mediated C–H cleavage. In the context of catalytic reaction development, protodepalladation offers a means of converting organopalladium(II) intermediates into organic products without a change in oxidation state at the metal center. Hence, when integrated into catalytic cycles, it can be a uniquely enabling elementary step. The goal of this review is to provide an overview of protodepalladation, including exploration of different reaction types, discussion of literature examples, and analysis of mechanistic features. Our hope is that this review will stimulate other researchers in the field to pursue new applications of this underexploited step in catalysis.1 Introduction2 Mechanistic Considerations3 Examples of Synthetically Enabling Protodepalladation Reactions3.1 Alkenylpalladium Species3.2 Arylpalladium Species3.3 Palladium Enolates3.4 Alkylpalladium Species4 Conclusion

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

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