Gold(I)-catalyzed asymmetric aldol reactions of isocyanoacetic acid derivatives with fluoroaryl aldehydes
作者:Vadim A. Soloshonok、Alexey D. Kacharov、Tamio Hayashi
DOI:10.1016/0040-4020(95)00893-d
日期:1996.1
enantiomeric excess (up to 63% of cis with 86–90% ee). In contrast to this, aldolreactions of isocyanoacetamide with fluoro-benzaldehydes provide dominant formation of trans-oxazolines (77–92% of trans with 80–94% ee) in all cases studied. The observed unusual stereodifferentiation in the reaction of methylisocyanoacetate with polyfluorobenzaldehydes is rationalized on the basis of an electron donor—acceptor
Asymmetricaldolreaction of α-ketoesters (RCOCOOMe: R = Me, i-Bu, Ph) with methyl isocyanoacetate or N, N-dimethyl-α-isocyanoacetamide in the presence of 1 mol% of a chiral (aminoalkyl) ferrocenylphosphine-gold(I) catalyst proceeded with high enantioselectivity to give corresponding oxazolines of up to 90% ee, which were converted into optically active β-alkyl-β-hydroxyaspartic acid derivatives.
Nitroalkenes, or their β-acetoxynitro precursors, react with α-isocyanoacetate esters in the presence of base to give high yields of 5-unsubstituted pyrroles; some important pyrroles are easily synthesised by this method.
The catalytic reaction of biaryl lactams with activated isocyanides is reported for the first time. By employing a cooperative catalytic system, oxazole-containing axially chiral biaryl anilines were obtained in high yields with excellent enantioselectivities. The key to the success lies in the atroposelective amide C–N bondcleavage with activated isocyanides.
reaction between biaryl thionolactones and activated isocyanides is reported. Under auto-tandem silver catalysis, both tri- and tetra-ortho-substituted biaryls were obtained in high yields and enantioselectivities. These products could be converted to bridged biaryls bearing an eight-membered lactone. Mechanistic studies provided key insights into the cause of this unusual torsional strain-independent