Functionalization Including Fluorination of Nitrogen-Containing Compounds Using Electrochemical Oxidation.
作者:Masakazu SONO、Naoko TOYODA、Kahori SHIMIZU、Eiji NODA、Yoshikazu SHIZURI、Motoo TORI
DOI:10.1248/cpb.44.1141
日期:——
Nitrogen-containing compounds have been subjected to electrochemical oxidation with Et3N-3HF as an electrolyte. Caffeine afforded 8-fluorocaffeine as a sole product in 40.3% yield. Guanosine tetraacetate and uridine triacetate gave the fluorinated compounds in 17.5 and 4.6% yields, rspectively. Similar electrochemical oxidation of caffeine with methanol, KCl, or KCN afforded 8-methoxycaffeine, 8-chlorocaffeine, or 8-cyanocaffeine, respectively.
The electrochemicalfluorination of a variety of N-protected lactams was carried out and Et3N–5HF was found to be superior to Et3N–3HF as the electrolyte. When 5- and 6-membered N-acetyl or ethoxycarbonyl lactams were used as substrates, the fluorination reaction selectively took place at the α-position of the lactam nitrogen and the corresponding monofluoro products could be obtained in good yields