scholarly journals n-Alkanes to n-alcohols: Formal primary C─H bond hydroxymethylation via quadruple relay catalysis

2020 ◽  
Vol 6 (47) ◽  
pp. eabc6688
Author(s):  
Xinxin Tang ◽  
Lan Gan ◽  
Xin Zhang ◽  
Zheng Huang
Keyword(s):  
Transition Metal ◽  
Transition Metal Catalysts ◽  
Selective Synthesis ◽  
Chemical Transformations ◽  
One Pot ◽  
Olefin Isomerization ◽  
Discrete Transition ◽  
Potential Applicability ◽  
Molecular Catalysts

Nature is able to synergistically combine multiple enzymes to conduct well-ordered biosynthetic transformations. Mimicking nature’s multicatalysis in vitro may give rise to new chemical transformations via interplay of numerous molecular catalysts in one pot. The direct and selective conversion of abundant n-alkanes to valuable n-alcohols is a reaction with enormous potential applicability but has remained an unreached goal. Here, we show that a quadruple relay catalysis system involving three discrete transition metal catalysts enables selective synthesis of n-alcohols via n-alkane primary C─H bond hydroxymethylation. This one-pot multicatalysis system is composed of Ir-catalyzed alkane dehydrogenation, Rh-catalyzed olefin isomerization and hydroformylation, and Ru-catalyzed aldehyde hydrogenation. This system is further applied to synthesis of α,ω-diols from simple α-olefins through terminal-selective hydroxymethylation of silyl alkanes.

Environmentally friendly synthesis of secondary amines via one-pot reductive amination over a heterogeneous Co–Nx catalyst

2017 ◽  
Vol 41 (20) ◽  
pp. 11991-11997 ◽  
Author(s):  
Liang Jiang ◽  
Peng Zhou ◽  
Zehui Zhang ◽  
Quan Chi ◽  
Shiwei Jin
Keyword(s):  
Transition Metal ◽  
Reductive Amination ◽  
Environmentally Friendly ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Secondary Amines ◽  
Selective Synthesis ◽  
One Pot ◽  
Earth Abundant

The application of earth-abundant transition metal catalysts in the mild and selective synthesis of secondary amines via the reductive amination method is very challenging.

Catalytic synthesis of amines and N-containing heterocycles: Amidate complexes for selective C–N and C–C bond-forming reactions

2010 ◽  
Vol 82 (7) ◽  
pp. 1503-1515 ◽  
Author(s):  
Patrick Eisenberger ◽  
Laurel L. Schafer
Keyword(s):  
Transition Metal ◽  
Catalytic Synthesis ◽  
Transition Metal Catalysts ◽  
Selective Synthesis ◽  
High Oxidation State ◽  
Early Transition Metal ◽  
Bond Forming ◽  
Group 4 ◽  
High Oxidation ◽  
Bond Forming Reactions

The direct, 100 % atom-economic, and selective synthesis of amines is a challenging task that can be achieved, making use of early transition-metal catalysts. Here we report the synthesis and application of group 4 and 5 high-oxidation-state metal amidate complexes in catalytic C–N (hydroamination) and C–C (hydroaminoalkylation) bond-forming reactions to access substituted amines.

scholarly journals Straightforward Strategies for the Preparation of NH-Sulfox­imines: A Serendipitous Story

Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2525-2538 ◽  
Author(s):  
James Bull ◽  
Renzo Luisi ◽  
Leonardo Degennaro
Keyword(s):  
Transition Metal ◽  
Physicochemical Properties ◽  
Direct Synthesis ◽  
Transition Metal Catalysts ◽  
Hypervalent Iodine ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free ◽  
Recent Developments ◽  
New Procedures

Sulfoximines are emerging as valuable new isosteres for use in medicinal chemistry, with the potential to modulate physicochemical properties. Recent developments in synthetic strategies have made the unprotected ‘free’ NH-sulfoximine group more readily available, facilitating further study. This account reviews approaches to NH-sulfoximines, with a focus on our contribution to the field. Starting from the development of catalytic strategies involving transition metals, more sustainable metal-free processes have been discovered. In particular, the use of hypervalent iodine reagents to mediate NH-transfer to sulfoxides is described, along with an assessment of the substrate scope. Furthermore, a one-pot strategy to convert sulfides directly into NH-sulfoximines is discussed, with N- and O-transfer occurring under the reaction conditions. Mechanistic evidence for the new procedures is included as well as relevant synthetic applications that further exemplify the potential of these approaches.1 Introduction2 Strategies to Form NH-Sulfoximines Involving Transition-Metal Catalysts3 Metal-Free Strategies to Prepare NH-Sulfoximines4 Mechanistic Evidence for the Direct Synthesis of NH-Sulfoximines from Sulfoxides and Sulfides5 Further Applications6 Conclusion

Carbon dioxide chemistry: Examples and challenges in chemical utilization of carbon dioxide

2009 ◽  
Vol 81 (11) ◽  
pp. 2069-2080 ◽  
Author(s):  
Liang-Nian He ◽  
Jin-Quan Wang ◽  
Jing-Lun Wang
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal Catalysts ◽  
Solid Catalyst ◽  
Homogeneous Catalyst ◽  
Chemical Transformations ◽  
Organic Carbonates ◽  
Benign Synthesis ◽  
Solvent Free Conditions ◽  
Potential Applications ◽  
Molecular Catalysts

The development of catalytic methods for chemical transformation of CO2 into useful compounds is of paramount importance from a standpoint of C1 chemistry and so-called green chemistry. The kinetic and thermodynamic stability of CO2 molecule presents significant challenges in designing efficient chemical transformations based on this potential feedstock. In this context, efforts to convert CO2 to useful chemicals will inevitably rely on its activation through molecular catalysts, particularly transition-metal catalysts. Two preparative processes employing solid catalyst or CO2-philic homogeneous catalyst were devised for environmentally benign synthesis of organic carbonates and oxazolidinones under solvent-free conditions. Those processes represent pathways for greener chemical fixations of CO2 to afford industrial useful materials such as organic carbonates and oxazolidinones with great potential applications.

One-pot construction of sterically challenging and diverse polyarylphenols via transition-metal-free benzannulation and their potent in vitro antioxidant activity

2017 ◽  
Vol 15 (9) ◽  
pp. 2052-2062 ◽  
Author(s):  
Shizuka Mei Bautista Maezono ◽  
Tej Narayan Poudel ◽  
Yong Rok Lee
Keyword(s):  
Antioxidant Activity ◽  
Transition Metal ◽  
Antioxidant Activities ◽  
One Pot ◽  
Metal Free ◽  
Novel Synthesis ◽  
In Vitro Antioxidant Activity

One pot novel synthesis of highly functionalized polyarylphenols via benzannulation under transition-metal-free conditions and their antioxidant activities are described.

Selective synthesis and biological activity of triazine-porphyrins as potential anti-cancer agents

2010 ◽  
Vol 14 (02) ◽  
pp. 123-127 ◽  
Author(s):  
Shen-Chu Xiao ◽  
Chao-Zhou Liu ◽  
Wu-Kun Liu ◽  
Wen-Zhong Xie ◽  
Wei-Ying Lin ◽  
...  
Keyword(s):  
Hydroxyl Group ◽  
Selective Synthesis ◽  
One Pot ◽  
Similar Activity ◽  
H Nmr ◽  
Porphyrin Derivatives ◽  
Anti Cancer ◽  
New Compounds ◽  
Mcf 7

Ten new triazine-porphyrin derivatives were synthesized using a simple one-pot procedure from the reaction of tetraphenylporphyrin bearing a hydroxyl group with 2,4,6-trichloro-1,3,5-triazine, and then with amines or alcohols. The structures of the products were characterized by 1H NMR, LC/MS, UV-vis and elemental analysis. The cytotoxic activity of the triazine-porphyrin derivatives was evaluated in vitro against MCF-7 cell. All new compounds showed similar activity against MCF-7 cells in the absence of light when compared to 5-fluorouracil and hematoporphyrin.

scholarly journals Biocatalytic Syntheses of Antiplatelet Metabolites of the Thienopyridines Clopidogrel and Prasugrel Using Fungal Peroxygenases

2021 ◽  
Vol 7 (9) ◽  
pp. 752
Author(s):  
Jan Kiebist ◽  
Kai-Uwe Schmidtke ◽  
Marina Schramm ◽  
Rosalie König ◽  
Stephan Quint ◽  
...  
Keyword(s):  
Active Metabolite ◽  
Organic Molecules ◽  
Selective Synthesis ◽  
Porcine Liver ◽  
One Pot ◽  
Cellular Assays ◽  
Liver Esterase ◽  
Reaction Optimization ◽  
Sulfenic Acids

Antithrombotic thienopyridines, such as clopidogrel and prasugrel, are prodrugs that undergo a metabolic two-step bioactivation for their pharmacological efficacy. In the first step, a thiolactone is formed, which is then converted by cytochrome P450-dependent oxidation via sulfenic acids to the active thiol metabolites. These metabolites are the active compounds that inhibit the platelet P2Y12 receptor and thereby prevent atherothrombotic events. Thus far, described biocatalytic and chemical synthesis approaches to obtain active thienopyridine metabolites are rather complex and suffer from low yields. In the present study, several unspecific peroxygenases (UPOs, EC 1.11.2.1) known to efficiently mimic P450 reactions in vitro—but requiring only hydroperoxide as oxidant—were tested for biocatalytic one-pot syntheses. In the course of the reaction optimization, various parameters such as pH and reductant, as well as organic solvent and amount were varied. The best results for the conversion of 1 mM thienopyridine were achieved using 2 U mL−1 of a UPO from agaric fungus Marasmius rotula (MroUPO) in a phosphate-buffered system (pH 7) containing 5 mM ascorbate, 2 mM h−1 H2O2 and 20% acetone. The preparation of the active metabolite of clopidogrel was successful via a two-step oxidation with an overall yield of 25%. In the case of prasugrel, a cascade of porcine liver esterase (PLE) and MroUPO was applied, resulting in a yield of 44%. The two metabolites were isolated with high purity, and their structures were confirmed by MS and MS2 spectrometry as well as NMR spectroscopy. The findings broaden the scope of UPO applications again and demonstrate that they can be effectively used for the selective synthesis of metabolites and late-state diversification of organic molecules, circumventing complex multistage chemical syntheses and providing sufficient material for structural elucidation, reference material, or cellular assays.

scholarly journals One-Pot Synthesis of Cycloparaphenylenes

2020 ◽  
Vol 02 (04) ◽  
pp. 306-312
Author(s):  
Jan H. Griwatz ◽  
Hermann A. Wegner
Keyword(s):  
Transition Metal ◽  
Organic Synthesis ◽  
Organic Materials ◽  
Selective Synthesis ◽  
Coupling Reactions ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis

The preparation of cycloparaphenylenes ([n]CPPs) with their bent π-system poses a long-standing challenge in organic synthesis. In the current multi-step approaches to access CPPs, pre-angulated precursors were combined using transition metal-catalysed or mediated coupling reactions. Therefore, there is a long way to the realisation of the idea of an ‘ideal synthesis’. An easy and efficient synthesis of different [n]CPPs would represent a breakthrough, also pushing their incorporation into organic materials. By combining multiple steps in a one-pot approach, the overall time and workload can be drastically shortened. Herein, we present the application of this concept for the preparation of [6] and [9]CPP as a simple and fast alternative to current methods. By tuning the reaction conditions the selective synthesis of both [6] and [9]CPP was demonstrated.

scholarly journals One-pot synthesis of propynoates and propynenitriles

2017 ◽  
Vol 95 (2) ◽  
pp. 144-148 ◽  
Author(s):  
Fan Shu ◽  
Qingjuan Zheng ◽  
Wanrong Dong ◽  
Zhihong Peng ◽  
Delie An
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Functional Group ◽  
High Efficiency ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
One Pot ◽  
Efficient Transformation ◽  
One Pot Synthesis ◽  
Substituted Acetylenes

An efficient transformation towards propynoates and propynenitriles is herein described. The practical methodology was conducted at low temperature (–78 or –60 °C) in a one-pot manner with the assistance of base rather than any transition metal catalysts. The base-induced protocol exhibits good functional group tolerance (up to 28 examples) and high efficiency (up to 92% yields) towards substituted acetylenes of great synthetic significance, which was also well demonstrated by the gram-scale reactions.

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