专利号:US-11161827-B2 优先权日:2019-04-05 标 题 :Catalytic systems for stereoselective synthesis of chiral amines by enantiodivergent radical C—H amination 发明人:Zhang xiao-xiang; Lang kai 权利人:TRUSTEES BOSTON COLLEGE; THE TRUSTEES OF BOSTON COLLEGE 摘要:In one aspect, the disclosure relates to a mode of asymmetric induction in radical processes based on sequential combination of enantiodifferentiative H-atom abstraction and stereoretentive radical substitution. Also disclosed is an asymmetric system for stereoselective synthesis of strained 5-membered cyclic sulfamides via radical 1,5-C—H amination of sulfamoyl azides. The disclosed metalloradical system can control the degree and sense of asymmetric induction in the catalytic radical C—H amination in a systematic manner. The disclosed system is applicable to a broad scope of substrates with different types of C(sp 3 )—H bonds and exhibits reactivity and selectivity, providing access to both enantiomers of useful 5-membered cyclic sulfamides in a highly enantioenriched form. Also disclosed are catalysts useful in these processes. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.
专利号:US-7956011-B2 优先权日:2005-05-04 标题:Materials and methods for the photodirected synthesis of oligonucleotide arrays 发明人:SERAFINOWSKI PAWEL JERZY; GARLAND PETER BRYAN 权利人:CANCER RES INST ROYAL 摘要:Materials and methods for photodirected synthesis of oligonucleotide arrays on a solid substrate by photodirected synthesis are disclosed which employ a film formed from (i) a photoacid generator that on photolysis generates acid that is capable of directly removing the protecting group of the linker molecules or oligonucleotides and (ii) a polymer substantially lacking electronegative heteroatoms that are capable of hydrogen bonding with photogenerated acid. Methods of synthesizing an oligomer arrays are also described that use a film that restricts diffusion of reactants and products on the substrate during synthesis of the array and which includes a precursor of a deprotecting reagent. The method involves removing one or more of the non-required products of the deprotection reaction from the reactive array elements at which they are produced during the reaction, in order to displace the deprotection reaction towards completion.
专利号:US-5145957-A 优先权日:1988-03-18 标 题:Stereoselective synthesis of a chiral cis 3-beta hydrogen (3R) 4-aroyloxy azetidinone 发明人:TSCHAEN DAVID M; LYNCH JOSEPH E; LASWELL WILLIAM L; VOLANTE RALPH P; SHINKAI ICHIRO 权利人:MERCK & CO INC 摘要:A process is described for the stereocontrolled synthesis of (3R,4R)-3-[(1R)-1-hydroxyethyl]-4-benzoyloxyazetidin-2-ones and their derivatives by cycloaddition involving an imine and a ketone, generated from 3(S)-hydroxybutyrate which are useful intermediates in the synthesis of carbapenem antibiotics.
专利号:US-5512701-A 优先权日:1995-06-07 标题:Process for the synthesis of vinyl sulfenic acid derivatives 发明人:HOARD DAVID W; LUKE WAYNE D 权利人:LILLY CO ELI 摘要:The present invention is directed to a new process for the synthesis of vinyl sulfenic acid derivatives. These compounds are useful for the synthesis of benzo[b]thiophenes, in particular 2-aryl-benzo[b]thiophenes.
专利号:US-6022963-A 优先权日:1995-12-15 标 题:Synthesis of oligonucleotide arrays using photocleavable protecting groups 发明人:MCGALL GLENN H; NAM NGO QUOC 权利人:AFFYMETRIX INC 摘要:Novel compounds are provided which are useful as linking groups in chemical synthesis, preferably in the solid phase synthesis of oligonucleotides and polypeptides. These compounds are generally photolabile and comprise protecting groups which can be removed by photolysis to unmask a reactive group. The protecting group has the general formula Ar-C(R1)(R2)-O-C(O)- wherein: Ar is an optionally substituted fused polycyclic aryl or heteroaromatic group or a vinylogous derivative thereof; R1 and R2 are independently H, optionally substituted alkyl, alkenyl or alkynyl, optionally substituted aryl or optionally substituted heteroaromatic, or a vinylogous derivative of the foregoing; and X is a leaving group, a chemical fragment linked to Ar-C(R1)(R2)-O-C(O)- via a heteroatom, or a solid support; provided that when Ar is 1-pyrenyl and R1=R2=H, X is not linked to Ar-C(R1)(R2)-O-C(O)- via a nitrogen atom. Preferred embodiments are those in which Ar is a fused polycyclic aromatic hydrocarbon and in which the substituents on Ar, R1 and R2 are electron donating groups. A particularly preferred protecting group is the 'PYMOC' protecting group, pyrenylmethyloxycarbonyl, where Ar=pyrenyl and R1=R2=H. Also provided is a method of forming, from component molecules, a plurality of compounds on a support, each compound occupying a separate predefined region of the support, using the protected compounds described above.
专利号:EP-0269236-B1 优先权日:1986-10-24 标题:Process for synthesis of a chiral azetidinone 摘要:A process is described for the stereo-controlled synthesis of 3-(R)-3-[1'-(R)-hydroxyethyl]-4-(R)-benzoyl-2-oxo-1-aze tidines and their derivatives which are useful intermediates in the synthesis of carbapenem antibiotics.
参考标题:Microwave-Assisted Efficient Synthesis Of Polymethoxyacetophenones And Natural Polymethoxyflavones, And Their Inhibitory Effects On Melanogenesis 作者:Masao Tsukayama,Eiji Kusunoki,Mohammad M. Hossain,Yasuhiko Kawamura,Shinji Hayashi 摘要:Microwave-Assisted Friedel-Crafts Acetylation Of Polymethoxybenzenes With Acetic Anhydride In The Presence Of In(Cf 3 So 3 ) 3 Under Solvent-Free Conditions Was Achieved Rapidly To Give Polymethoxyacetophenones In High Yields. Microwave-Assisted Benzoylation Of 2'-Hydroxypolymethoxyacetophenones With Polymethoxybenzoyl Chlorides, Followed By The Rearrangement Of The Resulting Benzoates And The Final