Mechanistic Criteria for Cation Radical Reactions: Aminium Salt-Catalyzed Cyclopropanation
摘要:
Mechanistic studies of the cyclopropanation of a series of trans-stilbenes by ethyl diazoacetate catalyzed by two different triarylaminium salts decisively confirm a cation radical mechanism and rule out a hypothetical electrophilic mechanism. The elucidation of key aspects of these cation radical mechanisms, including kinetic vs equilibrium control of ionization and chain vs catalytic mechanisms, has also been achieved for these systems. New mechanistic criteria for the positive identification of cation radical mechanisms are proposed.
Catalyst-Controlled Highly Selective Coupling and Oxygenation of Olefins: A Direct Approach to Alcohols, Ketones, and Diketones
作者:Yijin Su、Xiang Sun、Guolin Wu、Ning Jiao
DOI:10.1002/anie.201303917
日期:2013.9.9
Oxygen? That's radical! A method for the direct synthesis of substituted alcohols, ketones, and diketones through a catalyst‐controlled highly chemoselective coupling and oxygenation of olefins has been developed. The method is simple and practical, can be switched by the selection of different catalysts, and employs molecular oxygen as both an oxidant and a reagent.
Compounds comprising Formula (I) or a pharmaceutically acceptable salt thereof, are disclosed, wherein J1, J2, U1, B, Y, and A are as described in claims 1-16. Methods, compositions, and medicaments related thereto are also disclosed, for treating glaucoma, inflammatory bowel disease and baldness.
Compounds comprising
or a pharmaceutically acceptable salt or a prodrug thereof,
are disclosed, wherein J
1
, J
2
, U
1
, B, Y, and A are as described.
Methods, compositions, and medicaments related thereto are also disclosed.
Highly Enantioselective Dynamic Kinetic Resolution of 1,2−Diarylethanols by a Lipase−Ruthenium Couple
作者:Mahn-Joo Kim、Yoon Kyung Choi、Sol Kim、Daeho Kim、Kiwon Han、Soo-Byung Ko、Jaiwook Park
DOI:10.1021/ol800163z
日期:2008.3.1
A practical procedure has been developed for the dynamickineticresolution of 1,2-diarylethanols. This procedure employs a highly enantioselective lipase from Pseudomonas stutzeri (trade name, lipase TL) as the resolutioncatalyst and a rutheniumcomplex as the racemizationcatalyst. Sixteen 1,2-diarylethanols have been efficiently resolved to provide their acetyl derivatives with good yields (95-97%)