2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO), N-Bromosuccinimide (NBS) and Bromine as Efficient Catalysts for Dithioacetalization and Oxathioacetalization of Carbonyl Compounds and Transdithioacetalization Reactions
作者:Nasser Iranpoor、Habib Firouzabadi、Hamid Reza Shaterian、M. A. Zolfigol
DOI:10.1080/10426500211712
日期:2002.5.1
6-tetrabromo-2,5-cyclohexadienone (TABCO), N-bromosuccinimide (NBS), and bromine as efficient catalysts for conversion of carbonyl compounds to their cyclic and acyclic dithioacetals and 1,3-oxathiolanes under mild reaction conditions are described. These catalysts are also used for efficient transdithioacetalization of acetals, diacetals, ketals, acylals, enamines, hydrazones, and oximes with high
Dehydration Reactions in Water. Surfactant-type Brønsted Acid-catalyzed Dehydrative Etherification, Thioetherification, and Dithioacetalization in Water
作者:Shu Kobayashi、Shinya Iimura、Kei Manabe
DOI:10.1246/cl.2002.10
日期:2002.1
Dehydration reactions such as etherification, thioetherification, and dithioacetalization are efficiently catalyzed by a surfactant-type Bronsted acid in water.
A mild process using a combination of TMSCl and NaI in acetonitrile is used to regenerate carbonyl compounds from a variety of dithiane and dithiolane derivatives. This easy to handle and inexpensive protocol is also efficient to deprotect oxygenated and mixed acetals as 1,3-dioxanes, 1,3-dioxolanes and 1,3-oxathianes quantitatively. As a possible extension of this method, it was also showed that
在乙腈中使用 TMSCl 和 NaI 组合的温和工艺用于从各种二噻烷和二硫戊环衍生物中再生羰基化合物。这种易于操作且价格低廉的方案还可以有效地将含氧和混合缩醛作为 1,3-二氧六环、1,3-二氧戊环和 1,3-氧杂环己烷进行定量脱保护。作为该方法的可能扩展,还表明作为腙、N-甲苯磺酰腙和酮时的氮化底物在这些条件下反应良好,以高产率得到预期的酮。本文提出的方法是现有方法的一个很好的替代方案,因为它不使用金属、氧化剂、还原剂、酸性或碱性介质,并且以高产率获得酮产物。
Solvent Free Thioacetalization of Carbonyl Compounds Catalyzed by Cu(OTf)<sub>2</sub>-SiO<sub>2</sub>
作者:R. Vijaya Anand、P. Saravanan、Vinod K. Singh
DOI:10.1055/s-1999-2635
日期:1999.4
Aldehydes and ketones were thioacetalyzed using 1,2-ethanedithiol in the presence of a catalytic amount of Cu(OTf)2-SiO2 under solvent free conditions in excellent yields.