摘要:
One aspect of the present invention relates to a method for the transition metal (e.g., Cu(I)) mediated amidation of C—H bonds using electron-rich aliphatic azides. In certain embodiments, the methods are useful for the C—H insertion of nitrenes generated and stabilized by a β-diketiminato metal catalyst. In certain embodiments, said nitrenes are generated from organoazides, or by oxidation of the corresponding amine. Another aspect of the present invention relates to olefin aziridination using said β-diketiminato metal catalysts. In addition, the methods of the present invention include stereoselective C—H bond aminations and olefin aziridinatons. In certain embodiments, the methods are conducted in an aerobic environment. In certain embodiments, the present invention relates to the use of O2 as an oxidant, wherein water is the byproduct of oxidation; this fact avoids the generation of toxic byproducts and renders the methods atom economical.
摘要:
Process for the manufacture of a cyclic diester of an alpha-hydroxyacid comprising heating the alpha-hydroxyacid at a temperature from 100 to 250° C. in the presence of at least one polyol and of at least one catalyst selected from the group consisting carboxylates and alkoxides of Ti, Zr, Al and Sn.
摘要:
A PEPCK inhibitor can include identifying a molecule that has a size capable of fitting into and interacting with the PEPCK binding site and at least one of the following: (a) a first terminal substituent having co-planar atoms acting as metal ligands to the active site metal ion PEPCK; (b) at least one of an atom or substituent at positions 2 or 3 from the first terminal substituent includes a neutral carbon center or include an oxygen, sulfur, selenium, or other atom with similar physiochemical properties; (c) at least one of an atom or substituent at positions 2 or 3 from the first terminal substituent is devoid of an electropositive atom or substituents; or (d) a second terminal substituent opposite of the first terminal substituent, said second terminal substituent having an atom that is a hydrogen boding acceptor and/or is negatively charged.
摘要:
Method for the production of L,L-, D,D-, D,L- and meso-dilactides, comprising the polycondensation and/or polytransesterification of an L-, D- or D,L-lactic acid or of esters thereof to polyesters of higher molecular weights of the L-, D- and D,L-lactic acid (polylactic acids) and cyclizing depolymerization of the polylactic acids to dilactides, wherein the polyesters of higher molecular weights of the L-, D- and D,L-lactic acids are produced in the presence of hydrolysis-stable metal compounds as catalyst.
摘要:
The present invention relates to a condensation and washing device with which in particular the process vapors which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerization device for the production of polylactide and also to a method for processing process vapors which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.
摘要:
Provided are 1) a polymer which is excellent in a reactivity to acid and a heat stability and which is less swollen in developing, 2) a compound shown below which is a raw material for the above polymer and 3) a photoresist composition which contains the above polymer and which is improved in LWR and excellent in a heat resistance. (wherein n represents an integer of 0 to 2; R1 represents a hydrogen atom, methyl or the like; R2 to R10 each represent independently a hydrogen atom, a linear alkyl group, a branched alkyl group or the like; and A and B each represent independently an oxygen atom or a sulfur atom).
摘要:
A cyclic alcohol of formula (II-1): wherein: R2, R3, and R4 are each independently a hydrogen atom, a linear alkyl group comprising 1 to 6 carbon atoms, a branched alkyl group comprising 3 to 6 carbon atoms, or a cyclic alkyl group comprising 3 to 6 carbon atoms; or R2 and R3 or R3 and R4 combine to form an alkylene group comprising 3 to 6 carbon atoms; m is 1 or 2; R5, R6, R7, R8, R9, and R10 are each independently a hydrogen atom, a linear alkyl group comprising 1 to 6 carbon atoms, a branched alkyl group comprising 3 to 6 carbon atoms, or a cyclic alkyl group comprising 3 to 6 carbon atoms; A is an oxygen atom; and B is an oxygen atom or a sulfur atom. In addition, a process for producing the cyclic alcohol of formula (II-1).
摘要:
The present invention provides a method of producing D-type lactide from liquid D-type lactic acid, and a method for producing D-type polylactic acid having a weight average molecular weight of about 50,000˜20,000 g/mol from the produced D-type lactide. The method of the present invention is advantageous in that D-type lactide can be obtained at a high yield by a simple method, compared to the conventional production methods. Consequently, production cost of D-type polylactic acid that is finally obtained from D-type lactide can be reduced.
摘要:
Disclosed is a method for manufacturing D-lactide from liquid D-lactic acid and a method for manufacturing D-polylactic acid with a weight-average molecular weight 50,000-20,000 g/mol from the prepared D-lactide. The disclosed method is advantageous in that D-lactide can be prepared in high yield through a relatively simple process as compared to the existing method. Thus, the cost for producing D-polylactic acid from the D-lactide can be reduced.
摘要:
The present disclosure provides methods for purifying p-dioxanone. In embodiments, crude p-dioxanone may be contacted with at least one isocyanate-functionalized scavenger. The at least one isocyanate-functionalized scavenger may react with hydroxyl compounds present with the crude p-dioxanone to form reaction products, in embodiments polyurethanes and/or polyureas, which may then be removed. The p-dioxanone thus obtained is of greater purity than the starting crude p-dioxanone.