The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

http://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.5b00482

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

Isatins As Privileged Molecules in Design and Synthesis of Spiro-Fused Cyclic Frameworks

Multicomponent reactions: advanced tools for sustainable organic synthesis

In recent years, tools for the development of new drugs have been dramatically improved. These include genomic and proteomic research, numerous biophysical methods, combinatorial chemistry and screening technologies. In addition, early ADMET studies are employed in order to significantly reduce the failure rate in the development of drug candidates. As a consequence, the lead finding, lead optimization and development process has gained marked enhancement in speed and efficiency. In parallel to this development, major pharma companies are increasingly outsourcing many components of drug discovery research to biotech companies. All these measures are designed to address the need for a faster time to market. New screening methodologies have contributed significantly to the efficiency of the drug discovery process. The conventional screening of single compounds or compound libraries has been dramatically accelerated by high throughput screening methods. In addition, in silico screening methods allow the evaluation of virtual compounds. A wide range of new lead finding and lead optimization opportunities result from novel screening methods by NMR, which are the topic of this review article.

Drug Discovery Today

Catalytic Enantioselective Formation of C−C Bonds by Addition to Imines and Hydrazones: A Ten-Year Update

Multicomponent reactions (MCRs) are one-pot reactions employing more than two starting materials, e.g. 3, 4, … 7, where most of the atoms of the starting materials are incorporated in the final product.1 Several descriptive tags are regularly attached to MCRs (Fig. 1): they are atom economic, e.g. the majority if not all of the atoms of the starting materials are incorporated in the product; they are efficient, e.g. they efficiently yield the product since the product is formed in one-step instead of multiple sequential steps; they are convergent, e.g. several starting materials combine in one reaction to form the product; they exhibit a very high bond-forming-index (BFI), e.g. several non-hydrogen atom bonds are formed in one synthetic transformation.2 Therefore MCRs are often a useful alternative to sequential multistep synthesis.






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Figure 1


Above: multistep syntheses can be divergent (sequential) or convergent; below: in analogy MCR reactions are convergent and one or two component reactions are divergent or less convergent.

Chemistry and Biology Of Multicomponent Reactions

Iridium(I)-catalyzed olefin isomerization in bis(allyl) ethers is integrated into a generally applicable strategy for affecting highly stereoselective Claisen rearrangements. Catalyzed alkene isomerization affords allyl vinyl ethers from easily prepared di(allyl) ethers; direct thermolysis of these reaction mixtures leads to highly diastereoselective [3,3] sigmatropic rearrangements affording syn-2,3-dialkyl-4-pentenal derivatives. An easily executed strategy for realizing asymmetric variants of the isomerization-Claisen rearrangement (ICR) reactions is also described.

Catalyzed Olefin Isomerization Leading to Highly Stereoselective Claisen Rearrangements of Aliphatic Allyl Vinyl Ethers

Chemistry and Biology of Multicomponent Reactions

Merging the catalytic asymmetric synthesis of di(allyl) ethers with ensuing olefin isomerization-Claisen rearrangement (ICR) reactions provides a convenient, two-step route to asymmetric aliphatic Claisen rearrangements from easily obtained starting materials These reactions deliver the 2,3-disubstituted 4-pentenal derivatives characteristic of aliphatic Claisen rearrangements with excellent relative and absolute stereocontrol A catalytic enantioselective synthesis of the (+)-calopin dimethyl ether demonstrates the utility of this reaction technology in asymmetric synthesis enterprises

Asymmetric claisen rearrangements enabled by catalytic asymmetric Di(allyl) ether synthesis.

Asymmetric cinchona alkaloid-catalyzed ketene-N-thioacyl imine cycloadditions afford enantioenriched cis-4,5-disubstituted 1,3-thiazin-6-one heterocycles with high absolute and relative stereocontrol. These cycloadditions enable a strategy for executing catalytic asymmetric direct Mannich additions to enolizable, unactivated imines. The ketene and imine reaction components are both generated in situ from readily available acid chlorides and α-amido sulfones, respectively.

Kan Wang

Papers

Chemistry and Biology Of Multicomponent Reactions

Catalyzed Olefin Isomerization Leading to Highly Stereoselective Claisen Rearrangements of Aliphatic Allyl Vinyl Ethers

Chemistry and Biology of Multicomponent Reactions

Asymmetric claisen rearrangements enabled by catalytic asymmetric Di(allyl) ether synthesis.

Catalytic asymmetric [4 + 2] cycloadditions of ketenes and N-thioacyl imines: alternatives for direct mannich reactions of enolizable imines.