872195-09-0Relevant articles and documents
Palladium(II)-catalyzed asymmetric coupling of allylic alcohols and vinyl ethers: Insight into the palladium and copper bimetallic catalyst
Kawamura, Yasufumi,Kawano, Yasuhiro,Matsuda, Tomohiro,Ishitobi, Yuta,Hosokawa, Takahiro
scheme or table, p. 3048 - 3053 (2009/08/08)
The use of PdX2, CuX2 (X = OAc, OCOCF3, or Cl), and catechol together with (S,S)-4,4'-bisbenzyl- 2,2'-bioxazoline under O2 induces the asymmetric coupling of cinnamyl alcohols and vinyl ethers to give (R)-(+)-2-alkoxy-4-benzylidenetetrahydrofurans in 40-53% ee (79% yield). The present study provides implications for the so-called Wacker catalyst of PdX2 and CuX2, in terms of that the anionic ligands (X) of Pd and Cu interchange between two metals.
Palladium(II)-catalyzed oxidative transformation of allylic alcohols and vinyl ethers into 2-alkoxytetrahydrofurans: Catechol as an activator of catalyst
Minami, Kimi,Kawamura, Yasufumi,Koga, Koichi,Hosokawa, Takahiro
, p. 5689 - 5692 (2007/10/03)
(Chemical Equation Presented) A highly effective synthesis of 2-alkoxytetrahydrofurans from allylic alcohols and vinyl ethers was achieved by using catalytic amounts of Pd(OAc)2, Cu(OAc)2, and catechol (1:1:2) under O2. The use of catechol as an activator of Pd(II)-Cu(II) catalyst has been unprecedented. The 2-alkoxytetrahydrofurans are formed via oxypalladation of allylic alcohols toward vinyl ethers followed by 5-exo cyclization of the resulting oxypalladation intermediate and subsequent β-Pd-H elimination. No 6-endo cyclization of the oxypalladation intermediate occurs.
