Asymmetric dearomative spirolactonization of naphthols using λ3-iodanes under chiral phase-transfer catalysis
作者:Kevin Antien、Guillaume Viault、Laurent Pouységu、Philippe A. Peixoto、Stéphane Quideau
DOI:10.1016/j.tet.2017.04.028
日期:2017.6
The asymmetric phase-transfer catalytic effect of chiral Cinchona alkaloid-derived quaternary ammonium salts was investigated in the context of the λ3-iodane-mediated dearomative spirolactonization of naphthols. The scope and limitations of this methodology were evaluated using various substrates, which were converted into spirolactones in good yields and with enantiomeric excesses up to 58%.
Dearomatization of Electron‐Deficient Phenols to
<i>ortho</i>
‐Quinones: Bidentate Nitrogen‐Ligated Iodine(V) Reagents
作者:Xiao Xiao、Nathaniel S. Greenwood、Sarah E. Wengryniuk
DOI:10.1002/anie.201909868
日期:2019.11.4
ortho‐quinones by direct oxidation of phenols. The reaction is enabled by a novel bidentate nitrogen‐ligated iodine(V) reagent, a previously unexplored class of compounds which we have termed Bi(N)‐HVIs. The reaction is extremely general and proceeds with excellent regioselectivity for the ortho over para isomer. Functionalization of the ortho‐quinone products was examined, resulting in a facile one‐pot synthesis
尽管其用途广泛,邻醌的合成仍然是一个重大挑战,特别是获得缺电子衍生物仍然是一个未解决的问题。这里报道了第一个通过酚类直接氧化合成缺电子邻醌的通用方法。该反应是通过一种新型双齿氮连接碘 (V) 试剂实现的,这是一类以前未开发的化合物,我们将其称为 Bi( N )-HVI。该反应非常普遍,并且对于邻位异构体和对位异构体具有优异的区域选择性。对邻醌产物的官能化进行了检查,从而实现了儿茶酚的简单一锅合成,以及多种杂原子亲核试剂的掺入。该方法代表了 Bi( N )-HVI的首次合成应用,并展示了它们作为进一步开发高反应性、高度可调的 I(V) 试剂的平台的潜力。
Enantioselective Intramolecular Dearomative Lactonization of Naphthols Catalyzed by Planar Chiral Iodoarene
Abstract A series of planar chiral iodoarenes based on [2.2]paracyclophane was synthesized. An efficient asymmetric intramolecular oxidativelactonization of naphthols enabled by a combination of these chiral iodoarenes and mCPBA as oxidant is reported. This reaction proceeds under mild conditions, allowing the formation of spirolactones bearing a tetrasubstituted stereocenter in moderate yields and
METHOD FOR PRODUCING AROMATIC COMPOUND HAVING RING STRUCTURE THAT INCLUDES NITROGEN ATOM OR OXYGEN ATOM
申请人:Ishihara Kazuaki
公开号:US20130338371A1
公开(公告)日:2013-12-19
The invention is a method for efficiently producing an aromatic compound by an intramolecular cyclization reaction, the aromatic compound having a ring structure that includes a nitrogen atom or oxygen atom. An aromatic compound composed of tert-butyl-2-(3-oxo-3-phenylpropyl)phenyl carbamate or another aniline derivative or the like, or an aromatic compound composed of 3-(1-hydroxynaphthalene-2-yl)propionic acid or another naphthol derivative or the like is made to react in a system to which an oxidizing agent and a quaternary ammonium salt represented by general formula (1) are fed. In the formula, X is an iodine atom; and R
1
, R
2
, R
3
and R
4
are each independently a C
1-30
hydrocarbon group in which some hydrogen atoms are optionally substituted with halogen atoms, or R
1
and R
2
may be combine to form a divalent organic group bonded to a nitrogen atom, and R
3
and R
4
may combine to form a divalent organic group bonded to a nitrogen atom.
Enantioselective Kita Oxidative Spirolactonization Catalyzed by In Situ Generated Chiral Hypervalent Iodine(III) Species
作者:Muhammet Uyanik、Takeshi Yasui、Kazuaki Ishihara
DOI:10.1002/anie.200907352
日期:2010.3.15
The iodines(III) have it: The rational design of a conformationally flexible C2‐symmetric iodosylarene catalyst has been used for the enantioselectiveKitaoxidativespirolactonization. The reaction occurs through secondary n–σ* or hydrogen‐bonding interactions between the chiral catalyst and the substrate. Mes=mesityl (2,4,6‐trimethylphenyl).