Clean inversion of configuration in the Pd-catalyzed cross-coupling of 2-bromo-1,3-dienes.
The Pd-catalyzed cross-coupling reaction of 2-bromo-1,3-dienes derived from alkyl aldehydes, especially with Cl2Pd(DPEphos) as a catalyst, proceeds with clean stereoinversion of the Br-bearing C=C bond to produce in high yields and in high stereoselectivity (>/=97-98%) conjugated Z,E dienes of potentially high utility in the synthesis of complex natural products. The observed stereoinversion cannot be readily accommodated by the widely accepted pi-sigma-pi rearrangement mechanism for isomerization of ordinary allylpalladium derivatives.
Herbert C. Brown Laboratories of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, USA.
Xingzhong
X
Zeng
Qian
Q
Hu
Mingxing
M
Qian
Ei-ichi
E
Negishi
D000475:Alkenes / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D006842:Hydrocarbons, Brominated / Q000138:chemical synthesis / Q000737:chemistry*; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D015032:Zinc / Q000737:chemistry
D000475:Alkenes; D006842:Hydrocarbons, Brominated; D009942:Organometallic Compounds; D010165:Palladium; D015032:Zinc