Rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction.
An interesting rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction was developed. A chiral atropisomeric dipyridyldiphosphane ligand was found to be highly effective in this system. This operationally simple protocol allows both catalyst and reactants to be handled under air without precautions. Various enynes were transformed to the corresponding bicyclic cyclopentenones in good yield and enantiomeric excess (up to 95 % ee). A study of the electronic effects of the enyne substrates revealed a correlation between the electronic properties of the substrates and the ee value obtained in the product of the Pauson-Khand-type reaction. A linear free-energy relationship was observed from a Hammett study.
Kwong
Fuk Yee
FY
Open Laboratory of Chirotechnology of the Institute of Molecular Technology for Drug Discovery and Synthesis, Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Hong Kong. bcfyk@inet.polyu.edu.hk
Li
Yue Ming
YM
Lam
Wai Har
WH
Qiu
Liqin
L
Lee
Hang Wai
HW
Yeung
Chi Hung
CH
Chan
Kin Shing
KS
Chan
Albert S C
AS
D000480:Alkynes / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000138:chemical synthesis*; D008956:Models, Chemical; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D000480:Alkynes; D006571:Heterocyclic Compounds; D014867:Water; D012238:Rhodium