一是关于反应动力学，exo构型原料的反应显著快于endo构型；二是关于产物结构，无论使用exo或者endo构型的原料，溶剂解反应的产物都是exo构型，同时从对映纯的原料出发总是得到外消旋的产物。Winstein指出降冰片独特的分子骨架，使得反应中exo构型原料比endo构型原料更加容易转化为一种包含“三中心–两电子”键（即三个...
Systematic changes in chemical shifts and coupling constants with electronegativity of the ligand by exocyclic substitution and with alteration of the molecular geometry by the replacement of sulfur by selenium are reported.Alexander Hepp andInstitute of ChemistryUniversity of OsnabrückRoger Blachnik...
2-3,当R为CO2Me时,反应却通过形式上的“7-endo-trig”形成产物,而且无6-exo-trig产物,如图所示 已知反应并不是直接经过7-endo-trig生成产物的,而是经过了6-exo-trig形成了中间体A,中间体A分子内反应成含有三元环的中间体B,B经金属迁移开三元环形成中间体C,C经β氢消除形成产物 写出A,B,C结构(要求立体化...
The crystal structure of an exo-selective Diels–Alderase was determined at 2.94 Å resolution. Based on the structure and computational investigation of the catalytic mechanism, we designed and prepared mutant enzymes that reverse the stereoselectivity from exo to endo. A combination of ...
Interactive 3D chemistry animations of reaction mechanisms and 3D models of chemical structures for students studying University courses and advanced school chemistry hosted by University of Liverpool
ChemInform Abstract: Synthesis and Behavior of endo- and exo-Benzocyclobutenonorborneneorganic chemistry, reviewbridged compoundsChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an...
然而,根据Baldwin规则5-exo-选择性环氧开环环化要优于6-endo-选择性(图1B),因此Nakanishi假说在化学层面上是很难实现的。MLP毒素和其他含四氢吡喃的天然产物的复杂、独特和有趣的结构,以及它们不同的生物活性和治疗潜力,激发了化学家开发新的方法来促进环氧化物的6-endo型选择性开环(图2A)。尽管在该领域已经...
A mixture of endo-H and exo-H isomers ( 1a and 1 b) of the (η 4 -C 5 Me 5 H)PtCl 2 complex was prepared by the reaction of K 2 PtCl 4 with C 5 Me 5 H in MeOH. The mixture of isomers reacts with CpTl in the presence of TiBF 4 to give a novel complex, [(η 4 ...
Interactive 3D animations of endo and exo adducts in Diels-Alder reaction mechanisms for students studying University courses
Why Are Endo vs Exo Products Favored in the Diels-Alder Reaction? Stereochemistry of the Diels-Alder Reaction The Intramolecular Diels Alder Reaction Regiochemistry In The Diels-Alder Reaction HOMO and LUMO In the Diels Alder Reaction The Diels-Alder Reaction ...