Enantioselective Baeyer–Villiger Oxidation Catalyzed by Palladium(II) Complexes with Chiral <i>P,N</i>-Ligands
作者:Andrei V. Malkov、Frédéric Friscourt、Mark Bell、Martin E. Swarbrick、Pavel Kočovský
DOI:10.1021/jo800246g
日期:2008.6.1
Asymmetric Baeyer–Villiger reaction of symmetrical cyclobutanones 1a−j with urea−hydrogen peroxide (UHP) can be catalyzed by a complex of Pd(II) and the new terpene-derived P,N-ligand 7. The resulting lactones 2a−j were obtained in high yields and with good enantioselectivity (≤81% ee).
New chiral pyrazine-based ligands for self-assembly reactions
作者:Thomas Bark、Helen Stoeckli-Evans、Alexander von Zelewsky
DOI:10.1039/b205563p
日期:2002.8.8
The syntheses of two families of ditopic N-heterocyclic ligands are described. All the compounds contain a central pyrazine ring connected to peripheral pyridine or bipyridine moieties, providing bipyridine- and terpyridine-like binding sites, respectively. Annellated terpene fragments render these metal chelators chiral. Thus they face the challenge of introducing stereoselectivity into the formation of chiral, multinuclear co-ordination species.
Modular pyridine-type P , N -ligands derived from monoterpenes: application in asymmetric Heck addition
作者:Andrei V Malkov、Marco Bella、Irena G Stará、Pavel Kočovský
DOI:10.1016/s0040-4039(01)00369-0
日期:2001.4
Novel (diphenylphosphinophenyl)pyridine ligands (+)-8, (+)-15, (-)-21, and (-)-26 were synthesized from (-)-beta -pinene, (+)-3-carene, (+)-2-carene, and (-)-alpha -pinene, respectively, via Krohnke annulation as the key step, and shown to effect less than or equal to 88% ee in Heck addition (27 --> 28). Ligands (+)-15 and (-)-21 are quasi-enantiomeric; ligands 8 and 26 can be prepared in both enantiomeric forms from (+)- and (-)-enantiomers of alpha- and beta -pinene, respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.
Arbuzov,B.A. et al., Doklady Chemistry, 1971, vol. 199, p. 690 - 692