Nickel-Catalyzed Deaminative Alkyl-Alkyl Cross-Coupling of Katritzky Salts with Cyclopropanols: Merging C-N and C-C Bond Activation.

Herein, we report a general and practical nickel-catalyzed deaminative alkylation of Katritzky salts with cyclopropyl alcohols via merging C-N and C-C bond activation. This protocol enables the formation of an alkyl-alkyl bond along with the generation of a versatile ketone functional group in a single operation, thus providing a convenient approach for accessing β-alkyl ketones. This reaction is distinguished by its high functional group tolerance, broad substrate scope, and efficient late-stage derivatization of complex bioactive molecules.

Polyethylene Incorporating Diels-Alder Comonomers: A "Trojan Horse" Strategy for Chemically Recyclable Polyolefins.

Polyolefins with periodic unsaturation in the backbone chain are sought after for synthesizing chemically recyclable polymers or telechelic polyolefin macromonomers. Here we introduce a bottom-up synthesis of unsaturated high-density polyethylene (HDPE) via copolymerization of ethylene with dimethyl 7-oxabicyclo[2.2.

Catalytic Chemical Recycling of Post-Consumer Polyethylene.

Among commercial plastics, polyolefins are the most widely produced worldwide but have limited recyclability. Here, we report a chemical recycling route for the conversion of post-consumer high-density polyethylene (HDPE) into telechelic macromonomers suitable for circular reprocessing. Unsaturation was introduced into HDPE by catalytic dehydrogenation using an Ir-POCOP catalyst without an alkene acceptor.

Chemically Recyclable Ester-Linked Polypropylene.

Polyolefins represent the largest class of commodity materials due to their excellent material properties; however, they have limited pathways to chemical recycling and are often difficult to mechanically recycle. Here we demonstrate a new catalyst for the isoselective copolymerization of propylene and butadiene capable of favoring 1,4-insertion over 1,2-insertion while maintaining good molecular weights and turnover frequencies. This isotactic propylene copolymer with main-chain unsaturation was depolymerized to a telechelic macromonomer using an olefin metathesis catalyst and 2-hydroxyethyl acrylate.

Method to eliminate the zero spectra in Fourier transform profilometry based on a cost function.

To increase the accuracy, speed, and robustness of 3D measurements in Fourier transform profilometry (FTP), this paper introduces a cost function according to the intrinsic features of the amplitude and frequency modulated (AF/M) signal and proposes two new algorithms to eliminate the background components of the fringe pattern based on the proposed cost function. Finally, the standard Fourier transform (FT) is used to calculate the phase of the pattern, which no longer contains background components. The two proposed methods are both data-driven and require no parameter adjustments in advance.