Saegusa Oxidation of Enol Ethers at Extremely Low Pd-Catalyst Loadings under Ligand-free and Aqueous Conditions: Insight into the Pd(II)/Cu(II)-Catalyst System
作者:Quan Zhu、Yunsong Luo、Yongyan Guo、Yushun Zhang、Yunhai Tao
DOI:10.1021/acs.joc.0c02987
日期:2021.4.16
system of Saegusa oxidation, which converts enolethers to the corresponding enals with a number of diverse substrates at extremely low catalyst loadings (500 mol ppm) under ligand-free and aqueous conditions, is described. Its synthetic utility was demonstrated by large-scale applications of the catalyst system to important nature molecules. This work allows Saegusa oxidation to become a highly practical
One‐Pot Preparation of C
<sub>1</sub>
‐Homologated Aliphatic Nitriles from Aldehydes through a Wittig Reaction under Metal‐Cyanide‐Free Conditions
作者:Masatoshi Ezawa、Hideo Togo
DOI:10.1002/ejoc.201700277
日期:2017.4.26
A one-pot protocol to obtain C1-homologated aliphatic nitriles was achieved by treating aromatic and aliphaticaldehydes with the (methoxymethyl)triphenylphosphonium ylide followed by hydrolysis of the resulting methyl vinyl ethers with pTsOH (Ts = para-toluenesulfonyl) and treatment with molecular iodine and aqueous ammonia under metal cyanide free conditions. Neopentyl-type nitriles, which could
A drastic increase in catalyst turnover number (TON) was accomplished in the cross-metathesis of tetrafluoroethylene (TFE) and vinyl ethers. Under a continuous flow of TFE, catalyst Ru7, which contains a seven-membered N-heterocyclic carbene (NHC) ligand, reached a TON of 4100; this is 2 orders of magnitude higher than the highest hitherto reported value. Mechanistic studies revealed that the expanded
Ozonolyses of vinyl ethers 1a–c in
CH2Cl2 in the presence of allylic and homoallylic
alcohols 3a–c give in each case the corresponding unsaturated
hydroperoxy acetals 4a–h, derived from capture of the carbonyl
oxides 2a–c by the unsaturated alcohols.
N-Halogenosuccinimide-mediated cyclisations of the
hydroperoxides give the corresponding 1,2,4-trioxanes and/or
1,2,4-trioxepanes, depending on the structure of the hydroperoxides and
the identity of the N-halogenosuccinimides.
Tandem Application of C–C Bond-Forming Reactions with Reductive Ozonolysis
作者:Rachel Willand-Charnley、Patrick H. Dussault
DOI:10.1021/jo3015775
日期:2013.1.4
Several variants of reductiveozonolysis, defined here as the in situ generation of aldehydes or ketones during ozonolytic cleavage of alkenes, are demonstrated to work effectively in tandem with a number of C–C bond-forming reactions. For reactions involving basic nucleophiles (1,2-addition of Grignard reagents, Wittig or Horner–Emmons olefinations, and directed aldol reactions of lithium enolates)