Abstract: The disclosure relates to the field of electronic materials, and in particular to a composite film of fluorinated polybenzoxazole (6FPBO) and triple-shelled mesoporous silica hollow spheres, and to its preparation and use. The composite film comprises fluorinated polybenzoxazole as a matrix and amino-functionalized triple-shelled mesoporous silica hollow spheres which are dispersed in the fluorinated polybenzoxazole matrix. A mass ratio of (amino-functionalized triple-shelled mesoporous silica hollow spheres)/(fluorinated polybenzoxazole) is 1/100 to 5/100. The composite film has excellent thermal stability and a lower dielectric constant.

Abstract: Disclosed herein is a process for achieving a palladium-catalyzed cyclative C(sp3)-H/C(sp2)-H coupling reaction using a native free carboxylic acid as a directing group, an amino acid ligand, and oxidant. The process is useful for synthesizing a range of biologically important scaffolds, including tetralins, chromanes, and indanes.

Abstract: Provided herein is a method of forming a beta-lactone from a carboxylic acid having a beta-carbon with a hydrogen atom disposed thereon. The method comprises contacting a carboxylic acid of formula (1) as described herein with an effective amount of a palladium(II) catalyst, an effective amount of an N-protected aminoacid ligand, and t-butylhydroperoxide in a solvent comprising hexafluoroisopropanol (HFIP), at about 60° C. to provide a beta-lactone of formula (2) as described herein.

Abstract: Provided herein is a method of forming a beta-lactone from a carboxylic acid having a beta-carbon with a hydrogen atom disposed thereon. The method comprises contacting a carboxylic acid of formula (1) as described herein with an effective amount of a palladium(I) catalyst, an effective amount of an N-protected aminoacid ligand, and t-butylhydroperoxide in a solvent comprising hexafluoroisopropanol (HFIP), at about 60° C. to provide a beta-lactone of formula (2) as described herein.

Abstract: The present disclosure relates to positioning methods. One example method includes receiving a first distance parameter, sent by a first AP and used to represent a first distance between the first AP and a first terminal device connected to the first AP at a first moment, and a second distance parameter, sent by a second AP and used to represent a second distance between the second AP and the first terminal device connected to the second AP at a second moment, where the first AP and the second AP are a same AP or different Aps, receiving a status parameter, where the status parameter includes speed information of the first terminal device within the time from the first moment to the second moment, and an included angle between a moving direction and a reference direction, and determining at least one of first coordinates or second coordinates.