Intramolecular carbonyl-ene reactions in the synthesis of peri-oxygenated hydroaromatics
作者:Shyam Basak、Dipakranjan Mal
DOI:10.1016/j.tet.2016.02.033
日期:2016.4
Suzuki coupling of 2-formylphenylboronic acids, are shown to provide cycloalkylidene ene products under acidic conditions. Susceptibility of the products to aromatization is manoeuvred by varying the reaction conditions and catalysts including binol-derived Brønsted acid catalysts. A peri-effect is identified as a controlling factor for the aromatizations. Several oxidative transformations of an ene product
作者:Daniel Knueppel、Jingyue Yang、Bo Cheng、Douglas Mans、Stephen F. Martin
DOI:10.1016/j.tet.2015.05.024
日期:2015.9
A total synthesis of the aglycone of IB-00208 was accomplished in 22 steps using a newly developed approach towards polycyclic 1,4-dioxygenated xanthones from benzocyclobutenones. The generality of this entry to xanthones was initially established on several model systems before it was successfully applied to the construction of the hexacyclic core of the natural product. A new and potentially general
Neutral Lithium Triflate (LiOTf) Efficiently Catalyzes Chemoselective Preparations of Cyclic and Acyclic Dithioacetals from Carbonyl Compounds, Acylals, and O,O-Cyclic and Open-Chain Acetals under Solvent-Free Conditions
作者:Habib Firouzabadi、Shahram Eslami、Babak Karimi
DOI:10.1246/bcsj.74.2401
日期:2001.12
An efficient and chemoselective preparation of cyclic and acyclic thioacetals from carbonyl compounds, cyclic and acyclic acetals and acylals in the presence of catalytic amounts of neutral lithium triflate and thiols undersolvent-freeconditions is described.
Total Synthesis of Methyl 1,5,8-Trimethoxy-1H-isochromene-3-carboxylate and Its Derivatives via Palladium-Catalyzed Annulation of 2-Alkynylbenzaldehydes
A 7-step totalsynthesis of methyl 1,5,8-trimethoxy-1H-isochromene-3-carboxylate and a 5-step synthesis of its C-3 derivatives are reported. Sonogashira coupling of 2-halobenzaldehydes with terminal acetylenes was employed to access 2-alkynylbenzaldehydes, which underwent a Pd-catalyzed annulation to afford the corresponding isochromene-containing products.
Stereoselective Synthesis of Kalafungin Based on CuI‐Catalyzed Tandem Reactions of Arylethynes Containing an Ortho‐(1‐Hydroxyethyl) Substituent with Alkyl Diazoacetates
An isochromene synthesis is developed utilizing a cascade reaction involving a CuI catalyzed coupling reaction between an alkyne and diazoacetate followed by allenoate isomerization and subsequent oxa-Michael addition. The cascade sequence was also demonstrated for the synthesis of naphthalenes. Furthermore, the methodology developed herein was applied toward a stereoselectivesynthesis of pyranonaphthoquinone
异色烯合成是利用级联反应开发的,该反应涉及炔烃和重氮乙酸酯之间的 CuI 催化偶联反应,然后是烯丙酸酯异构化和随后的氧杂-迈克尔加成。级联序列也被证明用于合成萘。此外,本文开发的方法应用于吡喃萘醌卡拉芬净的立体选择性合成。