Applications of 4,4‘-(Me<sub>3</sub>Si)<sub>2</sub>-BINAP in Transition-Metal-Catalyzed Asymmetric Carbon−Carbon Bond-Forming Reactions
作者:Masamichi Ogasawara、Helen L. Ngo、Takeshi Sakamoto、Tamotsu Takahashi、Wenbin Lin
DOI:10.1021/ol050834s
日期:2005.7.1
A recently developed BINAP derivative with trimethylsilyl substituents on the 4- and 4 '-positions of the binaphthyl skeleton, 2,2 '-bis-(diphenylphosphino)-4,4 '-bis(trimethylsilyl)-1,1 '-binaphthyl (tms-BINAP), was used in a variety of transition-metal-catalyzed asymmetric carbon-carbon bond-forming reactions. In pi-allylpalladium-mediated reactions, tms-BINAP gave better enantioselectivity than the unsubstituted BINAP, and the origin of the improved enantioselectivity was gained from an X-ray structural study of [Pd(eta(3)-C3H5)((R)-tms-BINAP)]CIO4.
Synthesis of fluorinated allenes via palladium-catalyzed monofluoromethylation using FBSM
Palladium-catalyzedmonofluoromethylation of substituted 2-bromo-1,3-dienes using fluorobis(phenylsulfonyl)methane (FBSM) as a pronucleophile gave previously unknown monofluoromethylated allenes in high yields, which are the isosteres of biologically attractive allenic alcohols.
A New Route to Methyl (<i>R,E</i>)-(−)-Tetradeca-2,4,5-trienoate (Pheromone of <i>Acanthoscelides</i> <i>obtectus</i>) Utilizing a Palladium-Catalyzed Asymmetric Allene Formation Reaction
A formal total synthesis of the sex attractant of male dried bean beetle, methyl (R,E)-(−)-tetradeca-2,4,5-trienoate, was achieved by a new efficient route utilizing the Pd-catalyzed asymmetric allene synthesis reaction. It was found that the atropisomeric biaryl bisphosphine (R)-segphos showed better enantioselectivity than (R)-binap in the Pd-catalyzed reaction for preparing alkyl-substituted axially