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。
MIRSADEGHI, SEID;RICKBORN, B., J. ORG. CHEM., 1985, 50, N 22, 4340-4345
作者:MIRSADEGHI, SEID、RICKBORN, B.
DOI:——
日期:——
Palladium/zinc co-catalyzed asymmetric transfer hydrogenation of oxabenzonorbornadienes with alcohols as hydrogen sources
作者:Fujie Ma、Jingchao Chen、Fan Yang、Madhuri Vikas Shinde、Yongyun Zhou、Baomin Fan
DOI:10.1039/c7ob00175d
日期:——
Asymmetric transfer hydrogenation of oxabenzonorbornadienes was realized by using alcohols as hydrogensources under a co-catalytic system of palladium and zinc. Both primary and secondary alcohols could serve as reductants and afforded enantiomerically enriched 1,2-dihydronaphth-1-ol products with high optical purities.
作者:Jaya S. Kudavalli、Derek R. Boyd、Dara Coyne、James R. Keeffe、David A. Lawlor、Aoife C. MacCormac、Rory A. More O’Ferrall、S. Nagaraja Rao、Narain D. Sharma
DOI:10.1021/ol1014027
日期:2010.12.3
initial conformations, one of which is stabilized by hyperconjugation amplified by an aromatic no-bond resonance structure (HOC6H6+ ↔ HOC6H5 H+). MP2 calculations and an unfavorable effect of benzoannelation on benzeniumion stability, implied by pKR measurements of −2.3, −8.0, and −11.9 for benzenium, 1-naphthalenium, and 9-phenanthrenium ions, respectively, support the explanation.
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。