A new and efficient approach for the synthesis of oxygen and nitrogen heterocycles by organoselenium catalysis has been developed. The exo-cyclization proceeded smoothly under mild conditions with good functional group tolerance and excellent regioselectivity. Mechanistic studies revealed that 1-fluoropyridinium triflate is key for oxidative cyclization.
Combination of Lewis Basic Selenium Catalysis and Redox Selenium Chemistry: Synthesis of Trifluoromethylthiolated Tertiary Alcohols with Alkenes
作者:Zechen Zhu、Jie Luo、Xiaodan Zhao
DOI:10.1021/acs.orglett.7b02406
日期:2017.9.15
A new and efficient method for diaryl selenide catalyzed vicinal CF3S hydroxylation of 1,1-multisubstitued alkenes has been developed. Various trifluoromethylthiolated tertiary alcohols could be readily synthesized under mild conditions. This method is also effective for the intramolecular cyclization of alkenes tethered by carboxylic acid, hydroxy, sulfamide, or ester groups and is associated with
Formation of COOH-Ylides, and Their Reactivities and Selectivities in Wittig Reactions
作者:Yuta Suganuma、Yuichi Kobayashi
DOI:10.1055/s-0037-1611958
日期:2019.2
Whereas two equivalents of base are typically required to prepare carboxylate (CO2 –) ylides [Ph3P+C–(H)-alk-CO2 –] (alk = alkanediyl) from carboxy (CO2H) phosphoniumsalts [(Ph3PCH2-alk-CO2H)+] X–, we reveal, for the first time, that carboxy ylides [Ph3P+C–(H)-alk-CO2H] can be generated with one equivalent of NaHMDS at 0 °C, and that the Wittig reaction of simple aliphatic aldehydes (1 equiv) with