内酯直接氢解为羧酸(即不接触羰基的C烷氧基-O键的氢解)通常是困难的,因为当前使用布朗斯台德酸作为催化剂的策略通常需要苛刻的条件,例如高温和高温H 2压力。在此,我们报告了已开发的无溶剂催化转化方法,其中W(OTf)6被认为可以促进氢解过程。该策略可以在特别温和的条件下(例如,反应温度<150°C和1 atm H 2的条件下)有效地将内酯氢化为羧酸),并显示出较宽的基材范围。另外,该催化方案可以进一步应用于作为可再生聚合物的聚羟基链烷酸酯的氢解成相应的直链羧酸。随后进行了广泛的机理研究,密度泛函理论计算揭示了一种反应模式,包括在W(OTf)6的帮助下C═O键的完全裂解催化剂。此外,通过电喷雾电离质谱已成功检测到该机理中产生的关键中间体,即具有OTf部分的moiety。通过与布朗斯台德酸催化体系的比较,研究证实了OTf部分的存在可以显着降低与重排和消除过程相关的障碍。同时,重点放在阴离子发挥
Methylenations of heteroatom-substituted carbonyls with dimethyl titanocene
作者:Nicos A. Petasis、Shao-Po Lu
DOI:10.1016/0040-4039(95)00320-c
日期:1995.4
Reaction of dimethyl titanocene with a variety of heteroatom-substituted carbonylcompounds, including: silylesters, anhydrides, carbonates, amides, imides, thioesters, selenoesters and acyl silanes gives the corresponding heteroatom-substituted alkenes.
[EN] 5-[(PIPERAZIN-1-YL)-3-OXO-PROPYL]-IMIDAZOLIDINE-2,4-DIONE DERIVATIVES AS ADAMTS INHIBITORS FOR THE TREATMENT OF OSTEOARTHRITIS<br/>[FR] DÉRIVÉS 5-[(PIPÉRAZINE-1-YL) -3-OXO-PROPYL]-IMIDAZOLIDINE -2,4-DIONE COMME INHIBITEURS D'ADAMTS POUR LE TRAITEMENT DE L'ARTHROSE
申请人:GALAPAGOS NV
公开号:WO2016102347A1
公开(公告)日:2016-06-30
The present invention discloses compounds according to Formula (I), wherein R, R2, R3a, R3b, and Cy are as defined herein. The present invention discloses compounds inhibiting ADAMTS, methods for their production, pharmaceutical compositions comprising the same and methods for the prophylaxis and/or treatment of inflammatory conditions and/or diseases involving degradation of cartilage and/or disruption of cartilage homeostasis.
[EN] 5-[3-[PIPERAZIN-1-YL]-3-OXO-PROPYL]-IMIDAZOLIDINE-2,4-DIONE DERIVATIVES AS ADAMTS 4 AND 5 INHIBITORS FOR TREATING E.G. OSTEOARTHRITIS<br/>[FR] DÉRIVÉS DE 5-[3-[PIPÉRAZIN-1-YL]-3-OXO-PROPYL]-IMIDAZOLIDINE-2,4-DIONE À UTILISER EN TANT QU'INHIBITEURS D'ADAMTS 4 ET 5 POUR TRAITER PAR EXEMPLE L'ARTHROSE
申请人:GALAPAGOS NV
公开号:WO2017211666A1
公开(公告)日:2017-12-14
The present invention discloses 5-[3-[piperazin-l-yl]-3-oxo-propyl]-imidazolidine-2,4-dione derivatives according to Formula (I), wherein R1, R2, R3a, R3b, R6a, R6b, the subscript n and Cy are as defined herein. The present invention relates to compounds inhibiting ADAMTS 4 and 5 for the prophylaxis or treatment of inflammatory diseases or diseases involving degradation of cartilage or disruption of cartilage homeostasis, such as e.g. osteoarthritis.
Synthesis of the taxol AB-system by olefination of an A-ring C1 ketone and direct B-ring closure
作者:David Crich、Swaminathan Natarajan、Joyce Z Crich
DOI:10.1016/s0040-4020(97)00411-0
日期:1997.5
Two syntheses of 13-deoxy-taxol C1 ketones are presented. Olefination of these C1 ketones is achieved, indirectly, via either the Meyer-Schuster reaction or by introduction of a vinyl group with vinylcerium dichloride followed by allylicrearrangement. Both methods provide the E-olefin exclusively. Dihydroxylation of these olefins is achieved with catalytic OsO4 and NMNO in moderate yield, providing