Methods for preparing active carbonate esters of water-soluble polymers are provided. Also provided are other methods related to the active carbonate esters of water-soluble polymers, as well as corresponding compositions.

Described herein are labeling agents, specifically [.sup.11C]fluoroform, [.sup.11C]difluoromethane, [.sup.11C]fluoromethyl iodide, [.sup.11C]fluoromethyl bromide, [.sup.11C]fluoromethyl chloride, [.sup.11C]fluoromethyl trifluoromethansulfonate, [.sup.11C]difluoromethyl iodide, [.sup.11C]difluoromethyl bromide, [.sup.11C]difluoromethyl chloride, [.sup.11C]difluoromethyl trifluoromethansulfonate, [.sup.11C]trifluoromethyl iodide, [.sup.11C]trifluoromethyl bromide, [.sup.11C]trifluoromethyl chloride, [.sup.11C]trifluoromethyl trifluoromethansulfonate, [.sup.18F]fluoroform, [.sup.18F]difluoromethane, [.sup.18F]difluoromethyl bromide or [.sup.18F]trifluoromethyl bromide. Also included are methods of labeling precursors to provide labeled fluoroalkanes and imaging methods.

A long life catalyst is provided that is conveniently and inexpensively capable of being produced and that is highly active and has inhibited metal leakage. According to aspects of the present invention, a catalyst is provided that includes: a polymer including a plurality of first structural units and a plurality of second structural units; and metal acting as a catalytic center, wherein at least part of the metal is covered with the polymer, each of the plurality of first structural units has a first atom constituting a main chain of the polymer and a first substituent group bonded to the first atom, a second atom included in each of the plurality of second structural units is bonded to the first atom, and the second atom is different from the first atom, or at least one of all substituent groups on the second atom is different from the first substituent group.

A long life catalyst is provided that is conveniently and inexpensively capable of being produced and that is highly active and has inhibited metal leakage. According to aspects of the present invention, a catalyst is provided that includes: a polymer including a plurality of first structural units and a plurality of second structural units; and metal acting as a catalytic center, wherein at least part of the metal is covered with the polymer, each of the plurality of first structural units has a first atom constituting a main chain of the polymer and a first substituent group bonded to the first atom, a second atom included in each of the plurality of second structural units is bonded to the first atom, and the second atom is different from the first atom, or at least one of all substituent groups on the second atom is different from the first substituent group.

The present invention relates to a process for the preparation of crisaborole of formula (I):

##STR00001##

by preparing intermediates of formulas (II) and (III):

##STR00002##

The present invention relates to a process for the preparation of crisaborole of formula (I): ##STR00001## by preparing intermediates of formulas (II) and (III): ##STR00002##

Methods of synthesizing compounds using CO.sub.2 as a directing group for CH functionalization, and compounds made thereby, are described.

Methods of synthesizing compounds using CO.sub.2 as a directing group for CH functionalization, and compounds made thereby, are described.

Provided is a method for preparing L-BPA, which includes steps of: reacting N-protected (S)-4-halophenylalanine of Formula I, a boronating agent, Grignard reagent and bis(2-dimethylaminoethyl)ether to obtain a reaction mixture, wherein the reaction mixture comprises N-protected (S)-4-boronophenylalanine of Formula II and the R.sup.2 group represents a protecting group; ##STR00001## isolating the N-protected (S)-4-boronophenylalanine from the reaction mixture; and deprotecting the R.sup.2 group of the N-protected (S)-4-boronophenylalanine to obtain L-BPA, wherein the L-BPA has a structure of Formula III.

Provided is a method for preparing L-BPA, which includes steps of: reacting N-protected (S)-4-halophenylalanine of Formula I, a boronating agent, Grignard reagent and bis(2-dimethylaminoethyl)ether to obtain a reaction mixture, wherein the reaction mixture comprises N-protected (S)-4-boronophenylalanine of Formula II and the R.sup.2 group represents a protecting group; ##STR00001## isolating the N-protected (S)-4-boronophenylalanine from the reaction mixture; and deprotecting the R.sup.2 group of the N-protected (S)-4-boronophenylalanine to obtain L-BPA, wherein the L-BPA has a structure of Formula III.