scholarly journals Organocatalysts for enantioselective synthesis of fine chemicals: definitions, trends and developments

2015 ◽  
Author(s):  
Chiara Palumbo
Keyword(s):  
Asymmetric Catalysis ◽  
Scientific Community ◽  
Organic Molecules ◽  
Optically Active ◽  
Enantioselective Synthesis ◽  
Fine Chemicals ◽  
Organic Transformations ◽  
Small Organic Molecules ◽  
Substrate Activation ◽  
High Yields

Organocatalysis, that is the use of small organic molecules to catalyse organic transformations, has been included among the most successful concepts in asymmetric catalysis and it has been used for the enantioselective construction of C-C, C-N, C-O, C-S, C-P, and C-halide bonds. Since the seminal works in early 2000, the scientific community has been paying an ever-growing attention to the use of organocatalysts for the synthesis, with high yields and remarkable stereoselectivities, of optically active fine chemicals of interest for the pharmaceutical industry. A brief overview is here presented about the two main classes of substrate activation by the catalyst: covalent organocatalysis and non-covalent organocatalysis, with a more stringent focus on some recent outcomes in the field of the latter and of hydrogen-bond-based catalysis. Finally, some successful examples of heterogenisation of organocatalysts are also discussed, in the view of a potential industrial exploitation.

scholarly journals Organocatalysts for enantioselective synthesis of fine chemicals: definitions, trends and developments

2015 ◽  
Keyword(s):  
Asymmetric Catalysis ◽  
Scientific Community ◽  
Organic Molecules ◽  
Optically Active ◽  
Enantioselective Synthesis ◽  
Fine Chemicals ◽  
Organic Transformations ◽  
Small Organic Molecules ◽  
Substrate Activation ◽  
High Yields

<p>Organocatalysis, that is the use of small organic molecules to catalyse organic transformations, has been included among the most successful concepts in asymmetric catalysis and it has been used for the enantioselective construction of C-C, C-N, C-O, C-S, C-P, and C-halide bonds. Since the seminal works in early 2000, the scientific community has been paying an ever-growing attention to the use of organocatalysts for the synthesis, with high yields and remarkable stereoselectivities, of optically active fine chemicals of interest for the pharmaceutical industry. A brief overview is here presented about the two main classes of substrate activation by the catalyst: covalent organocatalysis and non-covalent organocatalysis, with a more stringent focus on some recent outcomes in the field of the latter and of hydrogen-bond-based catalysis. Finally, some successful examples of heterogenisation of organocatalysts are also discussed, in the view of a potential industrial exploitation.</p>

scholarly journals Organocatalysts for enantioselective synthesis of fine chemicals: definitions, trends and developments

2015 ◽  
Author(s):  
Matteo Guidotti ◽  
Chiara Palumbo
Keyword(s):  
Asymmetric Catalysis ◽  
Organic Molecules ◽  
Optically Active ◽  
Fine Chemicals ◽  
Organic Transformations ◽  
Small Organic Molecules ◽  
Non Covalent Interactions ◽  
High Yields ◽  
Covalent Interactions ◽  
Covalent Activation

Abstract Organocatalysis, that is the use of small organic molecules to catalyze organic transformations, has been included among the most successful concepts in asymmetric catalysis, and it has been used for the enantioselective construction of C–C, C–N, C–O, C–S, C–P and C–halide bonds. Since the seminal works in early 2000, the scientific community has been paying an ever-growing attention to the use of organocatalysts for the synthesis, with high yields and remarkable stereoselectivities, of optically active fine chemicals of interest for the pharmaceutical industry. A brief overview is here presented about the two main classes of organocatalysis which are respectively characterized by covalent and non-covalent activation of the substrate. More detailed information about non-covalent interactions for organocatalysis are given. Finally, some successful examples of heterogenisation of organocatalysts are also discussed, in the view of a potential industrial exploitation.

The chemistry of stabilized clusters

1982 ◽  
Vol 308 (1501) ◽  
pp. 27-34 ◽  
Keyword(s):  
Electron Donor ◽  
Organic Molecules ◽  
Metal Cluster ◽  
Organic Substrates ◽  
Insertion Reactions ◽  
Donor Ligand ◽  
Small Organic Molecules ◽  
Wide Range ◽  
Metal Metal ◽  
High Yields

Studies of the chemistry of metal cluster complexes and, in particular, their reactions with small organic molecules, have been confined to relatively few systems. Among the reasons for this are: (i) not many clusters are easily synthesized in high yields; (ii) their reactions often give a multitude of products that are difficult to separate and characterize; (iii) the conditions required to bring about reactions often lead to fragmentation of the cluster into lower nuclearity (often mononuclear) species. One cluster whose chemistry has been extensively studied is [Os 3 H 2 (CO) 10 ]. This can be synthesized in high yields from [Os 3 (CO) 12 ] + H 2 (Knox et al. 1975) and reacts readily under mild conditions with a wide range of electron-donor molecules by virtue of its coordinative unsaturation (Shapley et al. 1975; Deeming & Hasso 1976; Adams & Golembeski 1979). Formally, one may consider that a metal—metal double bond is present, which is reduced to a single bond on coordination of an additional two-electron donor ligand such as an organophosphine. The presence of metal—hydrogen bonds in this cluster and the cluster’s ability to coordinate organic substrates enable it to undergo a wide variety of insertion reactions, leading to products that may be regarded as intermediates in the reduction of organic molecules by clusters (Deeming & Hasso 1975; Keister & Shapley 1975).

scholarly journals Aldehydes as powerful initiators for photochemical transformations

2020 ◽  
Vol 16 ◽  
pp. 833-857 ◽  
Author(s):  
Maria A Theodoropoulou ◽  
Nikolaos F Nikitas ◽  
Christoforos G Kokotos
Keyword(s):  
Transition Metal ◽  
Organic Synthesis ◽  
Organic Molecules ◽  
Photophysical Properties ◽  
Organic Transformations ◽  
Aliphatic Aldehydes ◽  
Small Organic Molecules ◽  
Photochemical Transformations ◽  
The Way

Photochemistry, the use of light to promote organic transformations, has been known for more than a century but only recently has revolutionized the way modern chemists are thinking. Except from transition metal-based complexes, small organic molecules have been introduced as catalysts or initiators. In this review, we summarize the potential that (aromatic or aliphatic) aldehydes have as photoinitiators. The photophysical properties and photoreactivity of benzaldehyde are initially provided, followed by applications of aldehydes as initiators for polymerization reactions. Finally, the applications to date regarding aldehydes as photoinitiators in organic synthesis are presented.

Microwave-assisted organo-catalyzed C-C and C-X (heteroatom) bond-forming reactions-An overview

2021 ◽  
Vol 08 ◽  
Author(s):  
Kantharaju Kamanna ◽  
Yamanappagouda Amaregouda
Keyword(s):  
Organic Molecules ◽  
Organic Transformations ◽  
Large Area ◽  
High Demand ◽  
Moisture Sensitivity ◽  
Small Organic Molecules ◽  
Bond Forming ◽  
Direct Benefits ◽  
Speed Up ◽  
Chemical Manufacture

: Organocatalysis defines small organic molecules exclusively containing carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorous atom to speed-up the chemical reactions. Researcher demonstrated large area of applications in various organic transformations catalyzed by the organocatalysts, due to their less moisture sensitivity and air, easy abundance, less polluting, not interfere with the final product and inexpensive. This highlights high demand and direct benefits in the pharmaceutical intermediate and fine chemical manufacture compared to other conventional transition metal and enzyme catalysts. This review article intends to compile literature reported application of the microwave accelerated organocatalyzed carbon-carbon and carbon–heteroatom bond formation reactions reported in the literature.

Enantioselective synthesis of chiral α,β-unsaturated γ-substituted butyrolactams by organocatalyzed direct asymmetric vinylogous Michael addition of α,β-unsaturated γ-butyrolactam to 2-enoylpyridines

2016 ◽  
Vol 14 (27) ◽  
pp. 6568-6576 ◽  
Author(s):  
Zhen-Hua Wang ◽  
Zhi-Jun Wu ◽  
Deng-Feng Yue ◽  
Yong You ◽  
Xiao-Ying Xu ◽  
...  
Keyword(s):  
Michael Addition ◽  
Optically Active ◽  
Enantioselective Synthesis ◽  
High Yields

Approach providing a series of optically active α,β-unsaturated γ-substituted butyrolactams in high yields with excellent diastereo- and enantioselectivities.

Hydrogel supported chiral imidazolidinone for organocatalytic enantioselective reduction of olefins in water

2016 ◽  
Vol 70 (4) ◽  
Author(s):  
Alessandro Sacchetti ◽  
Filippo Rossi ◽  
Arianna Rossetti ◽  
Roberto Pesa ◽  
Emanuele Mauri
Keyword(s):  
Asymmetric Synthesis ◽  
Asymmetric Catalysis ◽  
Medicinal Chemistry ◽  
Organic Molecules ◽  
Biological Properties ◽  
Good Activity ◽  
Small Organic Molecules ◽  
Enantioselective Reduction ◽  
Activated Olefins ◽  
First Time

AbstractChiral products play an important role particularly in the field of medicinal chemistry, where it is known that enantiomers often have very different biological properties and effects. One of the most powerful tool to obtain a product as a single enantiomer is asymmetric catalysis. Recently, organocatalysis, i.e. the use of small organic molecules to catalyze enantioselective transformations, has emerged as a prominent field in asymmetric synthesis. In this work, the use of hydrogels as a support for a chiral imidazolidinone organocatalyst (MacMillan catalyst) and its application in the reduction of activated olefins mediated by the Hantzsch ester is reported for the first time. Results showed a good activity of hydrogels in respect to both yield and enantioselection.

scholarly journals Organocatalytic atroposelective heterocycloaddition to access axially chiral 2-arylquinolines

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gongming Yang ◽  
Shaofa Sun ◽  
Zhipeng Li ◽  
Yuhan Liu ◽  
Jian Wang
Keyword(s):  
Drug Discovery ◽  
Asymmetric Synthesis ◽  
Vital Role ◽  
Optically Active ◽  
Enantioselective Synthesis ◽  
Chiral Amine ◽  
New Class ◽  
Axially Chiral ◽  
High Yields

AbstractAxially chiral heterobiaryls play a vital role in asymmetric synthesis and drug discovery. However, there are few reports on the synthesis of atropisomeric heterobiaryls compared with axially chiral biaryls. Thus, the rapid enantioselective construction of optically active heterobiaryls and their analogues remains an attractive challenge. Here, we report a concise chiral amine-catalyzed atroposelective heterocycloaddition reaction of alkynes with ortho-aminoarylaldehydes, and obtain a new class of axially chiral 2-arylquinoline skeletons with high yields and excellent enantioselectivities. In addition, the axially chiral 2-arylquinoline framework with different substituents is expected to be widely used in enantioselective synthesis.

Research Progress on the Catalytic Enantioselective Synthesis of Axially Chiral Allenes by Chiral Organocatalysts

2020 ◽  
Vol 24 (6) ◽  
pp. 694-708 ◽  
Author(s):  
Qing Han Li ◽  
Xin Jiang ◽  
Kun Wu ◽  
Rui Qiang Luo ◽  
Meng Liang ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Building Blocks ◽  
Enantioselective Synthesis ◽  
Research Progress ◽  
Organic Transformations ◽  
Chirality Transfer ◽  
Reaction Systems ◽  
Axially Chiral ◽  
Nucleophilic Reagents ◽  
Organic Catalysts

Chiral allenes are important structural scaffolds found in many natural products and drugs, and in addition, they also serve as building blocks for many organic transformations. The conventional methods for preparing chiral allenes rely on the resolution of racemic allenes and the chirality transfer between non-racemic propargylic derivatives and nucleophilic reagents. In recent years, the synthesis of chiral allenes by asymmetric catalysis has been achieved fruitful results. Among them, enantioselective synthesis of chiral allenes with chiral organic catalysts is particularly prominent. In this paper, the research progress of enantioselective synthesis of chiral allenes catalyzed by chiral organic catalysts in recent years is reviewed, including various reaction systems and synthesis applications.

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