Sulfhydrolysis of Acyl Ketene Dithioacetals: A Convenient Synthesis of β-Oxodithioesters
摘要:
beta-Oxodithioesters are obtained in. good yields from acyl ketenedithioacetals on treatment with hydrogen sulphide in the presence of boron trifluoride etherate in refluxing dioxane.
p -Toluenesulfonic acid-catalyzed metal-free formal [4 + 1] heteroannulation via N H/O H/S H functionalization: One-pot access to 2-aryl/hetaryl/alkyl benzazole derivatives
concise and direct one-pot [4 + 1] synthetic strategy for the construction of 2-substituted benzazoles such as benzoxazoles and benzothiazoles has been disclosed in high yields (80–98%) by cascade coupling reaction of 2-amino(thio)phenols with β-oxodithioesters. The current approach enables NH/OH/SH functionalization in one-pot under solventless condition leading to diverse benzazoles without use of any
通过2-氨基(硫代)的级联偶联反应,已公开了一种高产率(80-98%)的简洁,直接的一锅[4 +1]合成策略,用于构建2-取代的苯并唑,如苯并恶唑和苯并噻唑酚与β-氧二硫代酯。目前的方法可以在无溶剂条件下在一锅中实现N H / O H / S H官能化,从而无需使用任何外部金属即可产生多种苯并恶唑。各种各样的2-氨基(硫代)酚和β-氧二硫代酯均具有出色的官能团耐受性,可用于该转化。此外,我们通过证明其与DNA拓扑异构酶II抑制剂的多样化多样化的相容性,抢占了这一新策略的广泛含义。
Access to Fully Substituted Thiazoles and 2,3-Dihydrothiazoles via Copper-Catalyzed [4 + 1] Heterocyclization of α-(<i>N</i>-Hydroxy/aryl)imino-β-oxodithioesters with α-Diazocarbonyls
An efficient chemoselective practical route to fully substituted thiazoles and 2,3-dihydrothiazoles has been devised by [4 + 1] heterocyclization of α-(N-hydroxy/aryl)imino-β-oxodithioesters with in situ generated Cu-carbenoids of diazocarbonyls. The α-(N-hydroxy/aryl)imino-β-oxodithioesters are readily accessible by the reaction of β-oxodithioesters with nitrous acid/nitrosoarenes. The overall transformation
Herein, we unveiled the novel approach for the synthesis of α-oxoketene S,S- and N,S-acetals employing a Mitsunobuprotocol. A wide range of alcohols has been successfully utilized, enabling great tolerability to this reaction. A diverse set of β-keto(dithioesters/thioamides) bearing various functional groups were found to be well suited substrates for this reaction, showing no obvious electronic effect
A new general method for the synthesis of thiophenes through acid mediated cyclization of mixed acetals derived from β-oxodithiates and bromoacetaldehyde acetal
presence of anhydrous potassium carbonate in dimethyl formamide at 80 °C to yield the corresponding mixed acetals. These acetals undergo smooth cyclization in the presence of ethanolic orthophosphoric acid to afford the corresponding 2-methylthio-3-acyl/aroyl/heteroaroyl thiophenes in 64–85% high overall yields.
operationally simple and user-friendly one-pot domino protocol for the synthesis of 2-aryl/hetaryl benzimidazoles has been devised from easily available and inexpensive 1,2-phenylenediamines and βoxodithioesters. The strategic [4+1] heteroannulation initiated by Brønsted acid PTSA relies on remarkable domino sequence of condensation, cyclization, and elimination. The current approach enables N-H/N-H functionalization