The first total synthesis of the highly complex and potent anticancer agent haouamine A is reported through an eight-step sequence. Brevity of the sequence and complete control of chemo-, position-, and stereoselectivity (both planar and axial chirality) were possible through the invention of chemistry specifically tailored for the problems at hand, namely a cascade annulation proceeding via a hitherto unknown chemical entity for the indeno-tetrahydropyridine ring system as well as a pyrone-assisted stitching of the daunting bent-aromatic ring.
(+)-Iso-A82775C是chloropupukeananin家族的拟议生物合成前体,并且是相关天然产物的重要中间体。描述了(+)-iso-A82775C的第一个对映选择性全合成(18个步骤,总收率2.2%),最终实现了仿生全氯丁酮的合成。关键步骤是(1)使用金鸡宁作为有机催化剂,对4-溴-3-羟基-2-吡喃酮与2-氯丙烯酸甲酯的对映选择性Diels-Alder反应,以及(2)抗选择性Cu介导的S N 2'反应得到轴向手性乙烯基烯丙基部分。
Asymmetric Diels−Alder Reactions of 2-Pyrones with a Bifunctional Organic Catalyst
作者:Yi Wang、Hongming Li、Yong-Qiang Wang、Yan Liu、Bruce M. Foxman、Li Deng
DOI:10.1021/ja070859h
日期:2007.5.1
The reactions of 2-pyrones with electron-deficient dienophiles constitute a synthetically useful class of Diels−Alder reaction. By exploring cinchona alkaloid-derived organic molecules as acid−base bifunctionalcatalysts, we successfully developed the first highly enantioselective and diastereoselective catalytic Diels−Alder reaction with 2-pyrones. Furthermore, we demonstrated the possibility of using
Synthesis of Highly Substituted Phenols and Benzenes with Complete Regiochemical Control
作者:Xiaojie Zhang、Christopher M. Beaudry
DOI:10.1021/acs.orglett.0c02157
日期:2020.8.7
Substitutedphenols are requisite molecules for human health, agriculture, and diverse synthetic materials. We report a chemical synthesis of phenols, including penta-substituted phenols, that accommodates programmable substitution at any position. This method uses a one-step conversion of readily available hydroxypyrone and nitroalkene starting materials to give phenols with complete regiochemical
Enantiodivergent [4+2] Cycloaddition of Dienolates by Polyfunctional Lewis Acid/Zwitterion Catalysis
作者:Vukoslava Miskov‐Pajic、Felix Willig、Daniel M. Wanner、Wolfgang Frey、René Peters
DOI:10.1002/anie.202009093
日期:2020.11.2
Different catalysis concepts have been reported, including dienophile activation by Lewis acids or H‐bond donors and diene activation by bases. Herein we report a new concept, in which an acidic prodiene is acidified by a Lewis acid to facilitate deprotonation by an imidazolium–aryloxide entity within a polyfunctional catalyst. A metal dienolate is thus formed, while an imidazolium–ArOH moiety probably
Effective One-Pot Synthesis of 5-Hydroxy-1,4-naphthoquinone Derivatives
作者:Sadao Tsuboi、Takuzo Komiyama、Yutaka Takaguchi
DOI:10.1055/s-2006-926417
日期:2006.5
In the presence of triethylamine, Diels-Alder reaction, involving decarboxylation-oxidation reaction of 3-hydroxy-2-pyrones with 1,4-benzoquinones gave 5-hydroxy-1,4-naphthoquinone derivatives in excellent to reasonable yields.
Synthesis of Anthraquinone Derivatives: Tandem Diels-Alder-Decarboxylation-Oxidation Reaction of 3-Hydroxy-2-pyrone with 1,4-Naphthoquinone
作者:Sadao Tsuboi、Takuzo Komiyama、Yutaka Takaguchi
DOI:10.1055/s-2005-922769
日期:——
In the presence of triethylamine, the Diels-Alder reaction of 3-hydroxy-2-pyrones with 1,4-naphthoquinones by a decarboxylation-oxidation process gave anthraquinonederivatives in good to excellent yields.