Highly Enantioselective Construction of 3-Hydroxy Oxindoles through a Decarboxylative Aldol Addition of Trifluoromethyl α-Fluorinated<i>gem</i>-Diols to<i>N</i>-Benzyl Isatins
An organocatalytic asymmetric direct aldoladdition reaction that involves cleavage of a carbon–carbon bond through the release of trifluoroacetate was developed. The protocol is wide in scope, generating the desired oxindoles of biological interest in nearly quantitative yields (up to 99 %) with excellent enantioselectivities (up to 98 % ee) and diastereoselectivities (up to 99:1 d.r.).
A metal-free oxidative coupling reaction of trifluoromethyl β-diketones with alcohols for the synthesis of α-keto esters in good to excellent yields has been developed. Preliminary mechanistic studies suggest that an I2/TBHP promoted sequential iodination, C–C bond cleavage, C–O bond formation and oxidation pathway is involved in this reaction.
A new organocatalytic asymmetric Michael addition reaction by cleavage of carbon‐carbon bonds through a mild release of trifluoroacetate has been developed. The reported method generates the decarboxylated γ‐nitro‐α‐fluorocarbonyl products with excellent enantioselectivies (up to 98% ee) and good diastereoselectivies (up to 20:1 dr).
thylation of alkenes with iododifluoromethylketones and TMSCN has been reported, which provides a particularly valuable route to access chiral β-difluoroacyl nitriles with excellent enantioselectivities. The method permits the efficient cyanation of varied β-difluoroacyl-benzylic radicals in mild conditions with high functional group tolerance. The reaction proceeds through a radical pathway. In order
An efficient and convenientsynthesis for mono-fluoroalkyl reagents α-halo-α-fluoroketones, including α-iodo-α-fluoroketones, α-bromo-α-fluoroketones and α-chloro-α-fluoroketones was reported by using the Wu–Colby's protocol involving the release of trifluoroacetate.