Indirect Cation Pool Method. Rapid Generation of Alkoxycarbenium Ion Pools from Thioacetals
作者:Seiji Suga、Kouichi Matsumoto、Koji Ueoka、Jun-ichi Yoshida
DOI:10.1021/ja0625778
日期:2006.6.1
the electrochemical generation and accumulation of ArS(ArSSAr)+ at low temperature (step 1) and the follow-up reaction with a thioacetal to generate an alkoxycarbeniumion pool (step 2), which reacts with various carbonnucleophiles (step 3). Steps 2 and 3 are extremely fast. The electrogenerated ArS(ArSSAr)+ was well-characterized by 1H NMR and CSI-MS. The alkoxycarbeniumion pool generated by the
Direct and indirect electrochemical generation of alkoxycarbenium ion pools from thioacetals
作者:Kouichi Matsumoto、Koji Ueoka、Shinkiti Suzuki、Seiji Suga、Jun-ichi Yoshida
DOI:10.1016/j.tet.2009.09.020
日期:2009.12
Thioacetals were found to be effective precursors to generate and accumulate alkoxycarbeniumions based on direct and indirect cation pool methods. Alkoxycarbeniumions thus generated reacted with carbonnucleophiles such as allylsilanes and enol silyl ethers to give C–C bond formation products in good yields.
Indirect Cation-Flow Method: Flash Generation of Alkoxycarbenium Ions and Studies on the Stability of Glycosyl Cations
作者:Kodai Saito、Koji Ueoka、Kouichi Matsumoto、Seiji Suga、Toshiki Nokami、Jun-ichi Yoshida
DOI:10.1002/anie.201100854
日期:2011.5.23
Go with the flow: The indirect cation‐flow method based on the generation of highly reactive organic cations from their precursors using electrochemically generated [ArS(ArSSAr)]+ was developed in flow microreactor systems (see scheme; Bn=benzyl, M=micromixer, R=microtube reactor). The method was applied to evaluate glycosyl cations such as A or their equivalents and glycosylation reactions.
electrochemical reactor that accomplishes electrolysis within a few seconds was developed, enabling flash generation of short-lived carbocations and trapping reaction with nucleophiles before they decompose. The present methodology was applied to highly reactive oxocarbenium ions, N-acyliminium ions, glycosyl cations, and the Ferrier cations. Moreover, continuous and flash synthesis of a pharmaceutical