苯-顺-和反-1,2-二氢二醇以显着不同的速率经历酸催化脱水:k cis / k trans = 4500。这可以通过形成不同初始构象的β-羟基碳正离子中间体来解释,其中之一是通过芳香族无键共振结构(HOC 6 H 6 + ↔ HOC 6 H 5 H +)放大的超共轭稳定。MP2 计算和苯并退火对苯离子稳定性的不利影响,由 p K R暗示对苯、1-萘和 9-菲离子分别测量的 -2.3、-8.0 和 -11.9 支持了这一解释。
high regio- and diastereoselectivity (>99:1), and excellent enantioselectivity (up to 99%ee). Symmetrical substitution patterns on the aromatic ring of the oxabenzonorbornadienes had no effect on the course of the reaction nor the enantioselectivity. The reaction produces an unusual stereochemical outcome for oxabicyclicringopenings since the trans rather than the cis product is formed. Very low catalyst
Hyperaromatic Stabilization of Arenium Ions: Acid-Catalyzed Dehydration of 2-Substituted 1,2-Dihydro-1-naphthols
作者:Jaya Satyanarayana Kudavalli、Dara Coyne、Rory A. More O’Ferrall
DOI:10.1021/jo2020483
日期:2012.1.6
correlation is taken to indicate that cis substuents are reacting normally, differentiated only by their inductive effects. The slower reactions of the trans isomers are the judged to be “abnormal”. This is confirmed by comparing effects of cis and trans β-OH substituents on the reactivities of dihydro phenols, naphthols, and phenanthrols. Whereas kH/kOH for cis substituents varies by less than 8-fold
Novel compounds and a novel process for their preparation
申请人:Fagnou Keith
公开号:US20050014721A1
公开(公告)日:2005-01-20
The present invention is directed to a procedure for making an enantiomerically enriched compound containing a hydronaphthalene ring structure. The process involves reacting oxabenzonorbornadienes with nucleophiles using rhodium as a catalyst and in the presence of a phosphine ligand. The compounds synthesized may be used in pharmaceutical preparations for the treatment of a variety of diseases and conditions.
Novel hydronaphthalene compounds, prepared by a rhodium catalysed ring opening reaction in the presence of phosphine ligand
申请人:AstraZeneca AB
公开号:EP1498406A1
公开(公告)日:2005-01-19
The present invention is directed to a procedure for making an enantiomerically enriched compound containing a hydronaphthalene ring structure. The process involves reacting oxabenzonorbornadienes with nucleophiles using rhodium as a catalyst and in the presence of a phosphine ligand. The compounds synthesized may be used in pharmaceutical preparations for the treatment of a variety of diseases and conditions.