The present invention relates to a process for the preparation of a compound of formula (I) wherein A.sub.1 and A.sub.2 are C—H, or one of A.sub.1 and A.sub.2 is C—H and the other is N; R.sub.1 is C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4haloalkyl or C.sub.3-C.sub.6cycloalkyl; each R.sub.2 is independently bromo, chloro, fluoro or trifluoromethyl; R.sub.3 is hydrogen; R.sub.4 is hydrogen, halogen, methyl, halomethyl or cyano; or R.sub.3 and R.sub.4 together form a bridging 1,3-butadiene group; R.sub.5 is chlorodifluoro-methyl or trifluoromethyl; n is 2 or 3; by reacting a compound of formula (II) wherein A.sub.1, A.sub.2, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and n is as defined under formula (I) above, with hydroxylamine, a base and a chiral catalyst, characterized in that the chiral catalyst is a dimeric chiral catalyst of formula (III) wherein R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and X are as defmed in claim 1.

##STR00001##

A process of converting a carbon-carbon multiple bond to a cyclopropane ring, comprising the addition of a N-alkyl-N-nitroso compound to a mixture of alkene precursor, aqueous base and Pd(II)-catalyst, with the N-alkyl-N-nitroso compound obtained directly from an alkyl amine derivative, NaNO.sub.2 and an acid via phase separation of the N-alkyl-N-nitroso compound from the aqueous phase.

The present invention discloses a diphenylamine-linked chiral bis(oxazoline) ligand without C.sub.2-symmetry of formula 3 and its synthesis method and application in an asymmetric catalytic reaction, wherein C.sub.2-symmetry is lost by introducing different groups into the diphenylamine backbone to realize precise control of “electronic effect” of the ligand backbone. An anthranilic acid derivative and an orthochlorobenzoic acid derivative are used as starting materials to prepare a compound of formula 1, and then the compound of formula 1 is reacted with a chiral amino alcohol compound to prepare a β-bishydroxy amide compound of formula 2, and the compound of formula 2 is further subjected to condensation to obtain the diphenylamine-linked chiral bis(oxazoline) ligand without C.sub.2-symmetry of formula 3. The present invention also provides an application of a catalyst formed by coordination of the diphenylamine-linked chiral bis(oxazoline) ligand without C.sub.2-symmetry with copper salt, zinc salt, nickel salt, iron salt or rhodium salt, in an asymmetric catalytic reaction.

##STR00001##

The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner.

The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

Synthetic methods are described herein operable to efficiently produce a wide variety of molecular species through conjugate additions via decarboxylative mechanisms. For example, methods of functionalization of peptide residues are described, including selective functionalization of peptide C-terminal residues. In one aspect, a method of peptide functionalization comprises providing a reaction mixture including a Michael acceptor and a peptide and coupling the Michael acceptor with the peptide via a mechanism including decarboxylation of a peptide reside.

The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner.

The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

The invention relates to a method for preparation of (meth)acrylic acid esters from (meth)acrylic acid anhydrides.

Disclosed are a method for synthesizing a thieno[3,2-b]pyridine-5(4H)-one derivative by using a gold catalyst and a use of the derivative compound, wherein the novel thieno[3,2-b]pyridine-5(4H)-one derivative of the present disclosure, which is a compound synthesized using gold as a catalyst, has fluorescence characteristics with a wide range of emission wavelengths and thus can be helpfully used in various industrial fields, such as physics, chemistry, and biomedicine research.

Synthetic methods are described herein operable to efficiently produce a wide variety of molecular species through conjugate additions via decarboxylative mechanisms. For example, methods of functionalization of peptide residues are described, including selective functionalization of peptide C-terminal residues. In one aspect, a method of peptide functionalization comprises providing a reaction mixture including a Michael acceptor and a peptide and coupling the Michael acceptor with the peptide via a mechanism including decarboxylation of a peptide reside.

Disclosed is a method for preparing a 1,3-dicarbonyl compound based on a metal hydride/palladium compound system. The method includes the following steps: suspending a palladium compound and a metal hydride in a solvent under the protection of nitrogen, then adding an electron-deficient olefin compound, reacting same at 0° C.-100° C. for 0.3 to 10 hours, then adding a saturated ammonium chloride aqueous solution to stop the reaction, and then subjecting same to extraction, evaporation until dryness, and column chromatography purification to obtain the 1,3-dicarbonyl compound. The hydride and palladium compound catalysts used by the present invention are reagents easily obtained in a laboratory. Compared to a common hydrogen hydrogenation method, the method is easier to operate, and has a higher safety, mild conditions, and a high reaction yield.