Highly efficient dynamic kinetic resolution of secondary aromatic alcohols with low-cost and easily available acid resins as racemization catalysts
作者:Yongmei Cheng、Gang Xu、Jianping Wu、Chensheng Zhang、Lirong Yang
DOI:10.1016/j.tetlet.2010.02.152
日期:2010.4
A new and efficient dynamic kineticresolution (DKR) process of secondary aromatic alcohols was developed with acid resins as racemization catalysts. Acid resin CD8604 was shown to have excellent racemization activity and good biocompatibility. When employing CD8604 and complex acyl donors as racemization catalyst and acyl donor, respectively, enantiomerically pure aromatic acetate was obtained with
4-(<i>N,N</i>-Dimethylamino)pyridine Hydrochloride as a Recyclable Catalyst for Acylation of Inert Alcohols: Substrate Scope and Reaction Mechanism
作者:Zhihui Liu、Qiaoqiao Ma、Yuxiu Liu、Qingmin Wang
DOI:10.1021/ol4030875
日期:2014.1.3
4-(N,N-Dimethylamino)pyridine hydrochloride (DMAP·HCl), a DMAP salt with the simplest structure, was used as a recyclablecatalyst for the acylation of inert alcohols and phenols under base-free conditions. The reaction mechanism was investigated in detail for the first time; DMAP·HCl and the acylating reagent directly formed N-acyl-4-(N′,N′-dimethylamino)pyridine chloride, which was attacked by the
Tropolonate Salts as Acyl-Transfer Catalysts under Thermal and Photochemical Conditions: Reaction Scope and Mechanistic Insights
作者:Demelza J. M. Lyons、Claire Empel、Domenic P. Pace、An H. Dinh、Binh Khanh Mai、Rene M. Koenigs、Thanh Vinh Nguyen
DOI:10.1021/acscatal.0c03702
日期:2020.11.6
strong nucleophilicity and photochemical activity, can promote the coupling reaction between alcohols and carboxylic acid anhydrides or chlorides to give products under thermal or blue light photochemical conditions. Kinetic studies and density functional theory calculations suggest interesting mechanistic insights for reactions promoted by this acyl-transfer catalytic system.
Basic compound, resist composition and patterning process
申请人:——
公开号:US20040234884A1
公开(公告)日:2004-11-25
Resist compositions comprising basic compounds having an imidazole skeleton and a polar functional group have an excellent resolution and an excellent focus margin and are useful in microfabrication using electron beams or deep-UV light.
Disclosed are an 8-arm polyethylene glycol (PEG) derivative (formula 1), manufacturing method and modified bio-related substance thereby, wherein a tetravalent group U and four trivalent groups Ec form a highly symmetric octavalent central structure CORE0 together, Lc connects the octavalent center to eight PEG arms having polydiversity or monodiversity and having n1-n8 as the degrees of polymerization thereof. The terminal of one PEG chain is connected to at least one functional group F (k ≥ 1), and said PEG chain and F can be directly connected (g = 0) or connected with a divalent linking group L0 connected with a terminal branched group G (g = 1) therebetween. The latter provides more reacting sites to combine more pharmaceutical molecules, thereby increasing the drug loading capacity. The near-center symmetric structure of the derivative allows more precise control over the molecular weight during large-scale production, thereby facilitating acquisition of a product having a narrower molecular weight distribution. A bio-related substance modified thereby has a more uniform and controllable performance.