Enantioselective Allylation from Allene, a Petroleum Cracking Byproduct

2018 ◽  
Author(s):  
Richard Y. Liu ◽  
Yujing Zhou ◽  
Yang Yang ◽  
Stephen L. Buchwald
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Petroleum Refining ◽  
Rapid Development ◽  
Catalyst System ◽  
Environmentally Benign ◽  
Hydrocarbon Mixtures ◽  
Chemical Manufacturing ◽  
Earth Abundant ◽  
Specialized Equipment

<p>Allene (C3H4) gas is produced and separated on million-metric-ton scale per year during petroleum refining but is only rarely employed in chemical manufacturing. Meanwhile, the addition of an allyl group (C3H5) to ketone-containing molecules is among the most common</p> <p>and prototypical reactions in organic synthesis. Herein, we report that the combination of allene with environmentally benign hydrosilanes can replace harsher, more wasteful, and more</p> <p>expensive allylmetal reagents in enantioselective ketone allylation reactions. This process is catalyzed by an earth-abundant metal and commercially available ligands, operates without specialized equipment or pressurization, and tolerates a broad range of functional groups. Furthermore, the exceptional chemoselectivity of our catalyst system enables industrially relevant C3 hydrocarbon mixtures of allene with methylacetylene and propylene to be applied</p> <p>directly. Based on our strategy, we anticipate the rapid development of methods that leverage this unexploited feedstock as a surrogate for existing nucleophilic allylation reagents.</p>

Enantioselective Allylation from Allene, a Petroleum Cracking Byproduct

2018 ◽  
Author(s):  
Richard Y. Liu ◽  
Yujing Zhou ◽  
Yang Yang ◽  
Stephen L. Buchwald
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Petroleum Refining ◽  
Rapid Development ◽  
Catalyst System ◽  
Environmentally Benign ◽  
Hydrocarbon Mixtures ◽  
Chemical Manufacturing ◽  
Earth Abundant ◽  
Specialized Equipment

<p>Allene (C3H4) gas is produced and separated on million-metric-ton scale per year during petroleum refining but is only rarely employed in chemical manufacturing. Meanwhile, the addition of an allyl group (C3H5) to ketone-containing molecules is among the most common</p> <p>and prototypical reactions in organic synthesis. Herein, we report that the combination of allene with environmentally benign hydrosilanes can replace harsher, more wasteful, and more</p> <p>expensive allylmetal reagents in enantioselective ketone allylation reactions. This process is catalyzed by an earth-abundant metal and commercially available ligands, operates without specialized equipment or pressurization, and tolerates a broad range of functional groups. Furthermore, the exceptional chemoselectivity of our catalyst system enables industrially relevant C3 hydrocarbon mixtures of allene with methylacetylene and propylene to be applied</p> <p>directly. Based on our strategy, we anticipate the rapid development of methods that leverage this unexploited feedstock as a surrogate for existing nucleophilic allylation reagents.</p>

Copper Catalysts in the Synthesis of Five-membered N-polyheterocycles

2018 ◽  
Vol 15 (7) ◽  
pp. 940-971 ◽  
Author(s):  
Navjeet Kaur
Keyword(s):  
Transition Metal ◽  
Organic Synthesis ◽  
Copper Catalysts ◽  
Research Field ◽  
Chemoselective Synthesis ◽  
Specialized Equipment ◽  
Transition Metal Catalyzed ◽  
Synthetic Methodologies ◽  
Metal Catalyzed ◽  
Traditional Approaches

Background: Due to significant biological activity associated with N-, O- and S-heterocycles, a number of reports for their synthesis have appeared in recent decades. Traditional approaches require expensive or highly specialized equipment or would be of limited use to the synthetic organic chemist due to their highly inconvenient approaches. This review summarizes the applications of copper catalysts with the emphasis on their synthetic applications for nitrogen bearing polyheterocylces. In summary, this review article describes the synthesis of a number of five-membered poly heterocyclic rings. Objective: Nowadays new approaches that employ atom-economical and efficient pathway have been developed. The researchers are following natural models to design and synthesize heterocycles. The transition metal catalyzed protocols have attracted the attention as compared to other synthetic methodologies because they use easily available substrates to build multiple substituted complicated molecules directly under mild conditions. In organic synthesis, constituted by transition metal catalyzed coupling transformations are one of the most powerful and useful protocols. The N-heterocycles are synthesized by this convenient and useful tool. Conclusion: The efficient and chemoselective synthesis of heterocycles by this technique has appeared as an important tool. This review shows a highly dynamic research field and the employment of copper catalysts in organic synthesis. Several strategies have been pointed out in the past few years, to meet more sustainable, efficient and environmentally benign chemical products and procedures. The catalytic strategies have been the focus of intense research because they avoid the use of toxic reagents. Among these catalytic strategies, highly rewarding and an important method in heterocycles synthesis is metal catalyzed synthesis.

Metal and Non-Metal Catalysts in the Synthesis of Five-Membered S-Heterocycles

2019 ◽  
Vol 16 (2) ◽  
pp. 258-275 ◽  
Author(s):  
Navjeet Kaur
Keyword(s):  
Organic Synthesis ◽  
Biological Activities ◽  
Reaction Times ◽  
Research Field ◽  
Environmentally Benign ◽  
Metal Catalyst ◽  
Efficient Synthesis ◽  
Heterocyclic Molecules ◽  
The Past ◽  
Harsh Conditions

Background:A wide variety of biological activities are exhibited by N, O and S containing heterocycles and recently, many reports appeared for the synthesis of these heterocycles. The synthesis of heterocycles with the help of metal and non-metal catalyst has become a highly rewarding and important method in organic synthesis. This review article concentrated on the synthesis of S-heterocylces in the presence of metal and non-metal catalyst. The synthesis of five-membered S-heterocycles is described here.Objective:There is a need for the development of rapid, efficient and versatile strategy for the synthesis of heterocyclic rings. Metal, non-metal and organocatalysis involving methods have gained prominence because traditional conditions have disadvantages such as long reaction times, harsh conditions and limited substrate scope.Conclusion:The metal-, non-metal-, and organocatalyst assisted organic synthesis is a highly dynamic research field. For ßthe chemoselective and efficient synthesis of heterocyclic molecules, this protocol has emerged as a powerful route. Various methodologies in the past few years have been pointed out to pursue more sustainable, efficient and environmentally benign procedures and products. Among these processes, the development of new protocols (catalysis), which avoided the use of toxic reagents, are the focus of intense research.

scholarly journals Non-Enzymatic Desymmetrization Reactions in Aqueous Media

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 720
Author(s):  
Satomi Niwayama
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Functional Groups ◽  
Organic Compounds ◽  
Recent Progress ◽  
Aqueous Media ◽  
Building Blocks ◽  
Organic Reactions ◽  
Environmentally Benign ◽  
Enzymatic Desymmetrization

Symmetric organic compounds are generally obtained inexpensively, and therefore they can be attractive building blocks for the total synthesis of various pharmaceuticals and natural products. The drawback is that discriminating the identical functional groups in the symmetric compounds is difficult. Water is the most environmentally benign and inexpensive solvent. However, successful organic reactions in water are rather limited due to the hydrophobicity of organic compounds in general. Therefore, desymmetrization reactions in aqueous media are expected to offer versatile strategies for the synthesis of a variety of significant organic compounds. This review focuses on the recent progress of desymmetrization reactions of symmetric organic compounds in aqueous media without utilizing enzymes.

scholarly journals Cycloaddition of Thiourea- and Guanidine-Substituted Furans to Dienophiles: A Comparison of the Environmentally-Friendly Methods

2020 ◽  
Vol 3 (1) ◽  
pp. 57
Author(s):  
Luka Barešić ◽  
Davor Margetić ◽  
Zoran Glasovac
Keyword(s):  
High Pressure ◽  
Functional Groups ◽  
Organic Synthesis ◽  
High Speed ◽  
Environmentally Friendly ◽  
Microwave Assisted ◽  
Pressure Synthesis ◽  
Ultrasound Assisted ◽  
Substituted Furans ◽  
Guanidine Moiety

The cycloaddition strategy was employed in order to obtain a 7-oxanorbornene framework substituted with a guanidine moiety or its precursor functional groups: protected amine or thiourea. In order to optimize the conditions for the cycloaddition, several environmentally-friendly methods—microwave assisted organic synthesis, high pressure synthesis, high speed vibrational milling, and ultrasound assisted synthesis—were employed. The outcomes of the cycloaddition reactions were interpreted in terms of endo/exo selectivity, the conversion of the reactants to the product, and the isolated yields. In general, our results indicated the HP and HSVM approaches as the methods of choice to give good yields and conversions.

Preyssler heteropolyacid H14[NaP5W29MoO110]: A heterogeneous, green and recyclable catalyst used for the protection of functional groups in organic synthesis

2010 ◽  
Vol 161 (3) ◽  
pp. 355-362 ◽  
Author(s):  
Gustavo Romanelli ◽  
Diego Ruiz ◽  
Patricia Vázquez ◽  
Horacio Thomas ◽  
Juan C. Autino
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Recyclable Catalyst

scholarly journals Direct access to spirocycles by Pd/WingPhos-catalyzed enantioselective cycloaddition of 1,3-enynes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Long Li ◽  
Shan Wang ◽  
Pengfei Luo ◽  
Ran Wang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Enantioselective Synthesis ◽  
Direct Access ◽  
Cycloaddition Reactions ◽  
Drug Discovery And Development ◽  
Spirocyclic Compounds ◽  
And Control ◽  
By Products

AbstractSpirocycles play an important role in drug discovery and development. The direct, catalytic, and enantioselective synthesis of spirocycles from readily available starting materials and in an atom economic manner remains a highly sought-after task in organic synthesis. Herein, an enantioselective Pd-hydride-catalyzed cycloaddition method for the synthesis of spirocyclic compounds directly from two classes of commonly available starting materials, 1,3-enynes and cyclic carbon−hydrogen (C−H) bonds, is reported. The reactions employ a chiral Pd/WingPhos catalyst to both suppress the formation of bis-allenyl by-products and control the stereoselectivity. 1,3-Enynes are used as dielectrophilic four-carbon units in the cycloaddition reactions, which also enables an enyne substrate-directed enantioselectivity switch with good levels of stereocontrol. The present spirocycle synthesis tolerates a broad range of functional groups of 1,3-enyne substrates, including alcohols, esters, nitriles, halides, and olefins. A variety of diverse cyclic nucleophiles, including pharmaceutically important heterocycles and carbocycles, can be flexibly incorporated with spiro scaffolds.

Direct synthesis of adipic acid esters via palladium-catalyzed carbonylation of 1,3-dienes

Science ◽  
2019 ◽  
Vol 366 (6472) ◽  
pp. 1514-1517 ◽  
Author(s):  
Ji Yang ◽  
Jiawang Liu ◽  
Helfried Neumann ◽  
Robert Franke ◽  
Ralf Jackstell ◽  
...  
Keyword(s):  
Adipic Acid ◽  
Direct Synthesis ◽  
Reaction Network ◽  
Catalyst System ◽  
Environmentally Benign ◽  
Palladium Catalyzed ◽  
Bidentate Phosphine ◽  
Cost Efficient ◽  
Bidentate Phosphine Ligand ◽  
Acid Esters

The direct carbonylation of 1,3-butadiene offers the potential for a more cost-efficient and environmentally benign route to industrially important adipic acid derivatives. However, owing to the complex reaction network of regioisomeric carbonylation and isomerization pathways, a selective practical catalyst for this process has thus far proven elusive. Here, we report the design of a pyridyl-substituted bidentate phosphine ligand (HeMaRaphos) that, upon coordination to palladium, catalyzes adipate diester formation from 1,3-butadiene, carbon monoxide, and butanol with 97% selectivity and 100% atom-economy under industrially viable and scalable conditions (turnover number > 60,000). This catalyst system also affords access to a variety of other di- and triesters from 1,2- and 1,3-dienes.

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