Enantioselective rhodium-catalyzed coupling of arylboronic acids, 1,3-enynes, and Imines by alkenyl-to-allyl 1,4-rhodium(I) migration

A chiral rhodium complex catalyzes the highly enantioselective coupling of arylboronic acids, 1,3-enynes, and imines to give homoallylic sulfamates. The key step is the generation of allylrhodium(I) species by alkenyl-to-allyl 1,4-rhodium(I) migration

Regioselective Nickel-Catalyzed Reductive Couplings of Enones and Allenes

No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78305/1/anie_201004740_sm_miscellaneous_information.pd

3D Printed Parts and Mechanical Properties: Influencing Parameters, Sustainability Aspects, Global Market Scenario, Challenges and Applications

3D printing has evolved as a disruptive technology for fabrication of industrial components, however due to the intrinsic nature of the process, the mechanical strength of the parts developed by 3D printing is a subject of research. The economic and technical advantages offered by 3D printing makes it as a potential replacement for the conventional manufacturing processes, particularly for developing complex and optimized products. The current paper is structured to focus on the various processes of 3D printing used for the development of industrial products, the various process parameters involved in each process and their effect on the mechanical properties of these parts particularly fatigue, tensile, bending strength, etc. primarily focusing on polymeric materials. Further an important aspect of 3D printed parts i’e tribological properties have been highlighted. A systemic literature review related to these aspects has also been presented. A section highlights the various applications of these 3D printed parts particularly in medical, aerospace and automotive. A section also highlights the sustainability aspects of these 3D printed parts. The paper also highlights the possible future research areas, recommendations and challenges involved in developing 3D printed parts

Boraformylation and Silaformylation of Allenes

The boraformylation of allenes with B2(pin)2 and a formate ester as boron and formyl source, respectively, proceeds in the presence of a copper catalyst. The reaction selectively affords the corresponding β‐boryl β,γ‐unsaturated aldehydes in good to high yields. Furthermore, the silaformylation of allenes was achieved with a formate ester and PhMe2Si−B(pin) as the silicon source.Boron or silicon? Boraformylation and silaformylation reactions of allenes with formate esters smoothly proceed in the presence of a copper catalyst using B2(pin)2 and PhMe2Si−B(pin) as the boron and silicon source, respectively. These reactions selectively afford the corresponding β‐boryl and β‐silyl β,γ‐unsaturated aldehydes in good to high yields with excellent regioselectivity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137579/1/anie201611314-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137579/2/anie201611314_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137579/3/anie201611314.pd

Production & characterization of multi-walled carbon nanotube (carboxyl -functionalized) reinforced polyesters

This paper presents the study on the production and characterization of Carbooxyl functionalized Multi-Walled Carbon Nanotube (MWCNT) reinforced Polyester composite. The main objective of this study is to optimize the weight percentage of MWCNT in the composite and to optimize the sonication time of the composite. To determine the optimum weight percentage of MWCNT, samples with different weight percentage of MWCNT was prepared. The prepared samples were sonicated for one hour and were tested for its viscosity. From the result, the viscosity was the highest at 0.4wt % MWCNT. Hence, the optimum weight percentage of MWCNT is at 0.4wt % MWCNT. After optimizing the weight percentage of MWCNT, the sonication time was optimized. This was done by preparing samples of 0.4wt % MWCNT which was then sonicated at different time intervals. After sonication, the viscosity was determined. From the result, the viscosity was the highest for the sample that was sonicated for 90 minutes. Hence, the optimum sonication time of 0.4wt % MWCNT is 90 minutes. After optimization, the composite was then characterized using Tensile Strength (TS) test, Thermal Gravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). From the Tensile Strength test, it can be concluded that the composite with 0.4wt % MWCNT was stronger than the sample without MWCNT. Due to its high mechanical strength and other unique properties, this Polyester composite has the potential to be used in various applications

Organic super-electron-donors : initiators in transition metal-free haloarene-arene coupling

Recent papers report transition metal-free couplings of haloarenes to arenes to form biaryls, triggered by alkali metal tert-butoxides in the presence of various additives. These reactions proceed through radical intermediates, but understanding the origin of the radicals has been problematic. Electron transfer from a complex formed from potassium tert-butoxide with additives, such as phenanthroline, has been suggested to initiate the radical process. However, our computational results encouraged us to search for alternatives. We report that heterocycle-derived organic electron donors achieve the coupling reactions and these donors can form in situ in the above cases. We show that an electron transfer route can operate either with phenanthrolines as additives or using pyridine as solvent, and we propose new heterocyclic structures for the respective electron donors involved in these cases. In the absence of additives, and with appropriate substrates, the coupling reactions are still successful although more sluggish,, and benzynes are proposed to play crucial roles in the initiation process in these cases