Cobalt-catalysed asymmetric hydrovinylation of 1,3-dienes
作者:Yam N. Timsina、Rakesh K. Sharma、T. V. RajanBabu
DOI:10.1039/c5sc00929d
日期:——
of bidentate 1,n-bis-diphenylphosphinoalkane-CoCl2 complexes Cl2Co[P~P]} and Me3Al or methylaluminoxane, acyclic (E)-1,3-dienes react with ethylene (1 atmosphere) to give excellent yields of hydrovinylation products. The regioselectivity (1,4- or...
Co-ordination chemistry of higher oxidation states. Part 33. Five-co-ordinate diphosphine complexes of cobalt(III), [Co{Ph2P(CH2)nPPh2}X3] (n = 4 or 5, X = Cl or Br)
作者:William Levason、Mark D. Spicer
DOI:10.1039/dt9900000719
日期:——
Oxidation of [CoPh2P(CH2)nPPh2}X2] (n = 4 or 5, X = Cl or Br) with NOX in CH2Cl2 produces intensely coloured [CoPh2P(CH2)nPPh2}X3], which are rare examples of five-co-ordinatecobalt(III) complexes. The complexes have been characterised by analysis, magnetic measurements (μeff. = ca. 3), i.r. and u.v.–visible spectroscopies. First co-ordination sphere bond lengths for the complexes with n = 4 have
Catalytic Enantioselective Hetero-dimerization of Acrylates and 1,3-Dienes
作者:Stanley M. Jing、Vagulejan Balasanthiran、Vinayak Pagar、Judith C. Gallucci、T. V. RajanBabu
DOI:10.1021/jacs.7b10055
日期:2017.12.13
counterion, and solventeffects uncovered during the course of these investigations show a unique role of a possible cationic Co(I) intermediate in these reactions. The rational evolution of a mechanism-based strategy that led to the eventual successful outcome and the attendant support studies may have further implications for the expanding use of low-valent group 9 metal complexes in organic synthesis