31518-14-6Relevant articles and documents
Convenient synthesis of cyclic α-alkoxyl-α,β-unsaturated carboxylic acids by nickel-catalyzed electrochemical carboxylation of lactone enol triflates
Senboku,Kanaya,Tokuda
, p. 140 - 142 (2002)
Electrochemical carboxylation of lactone enol triflates in DMF containing a catalytic amount of NiBr2·bpy with a platinum cathode and a magnesium anode under an atmospheric pressure of CO2 gave the corresponding cyclic α-alkoxyl-α,β-
Asymmetric Nazarov Cyclizations Catalyzed by Chiral-at-Metal Complexes
Mietke, Thomas,Cruchter, Thomas,Larionov, Vladimir A.,Faber, Tabea,Harms, Klaus,Meggers, Eric
supporting information, p. 2093 - 2100 (2018/04/19)
The application of Lewis acidic chiral-at-metal complexes of iridium(III) and rhodium(III) as catalysts for the asymmetric polarized Nazarov cyclization of dihydropyran- and indole-functionalized α-unsaturated β-ketoesters is reported (overall 24 examples). For both substrate classes, catalyst loadings of 2 mol% were found to be sufficient for achieving high yields and high stereoselectivities. The cyclized dihydropyran products were isolated in 85–98% yield, with 89%–>99% ee, and trans/cis ratios of 15:1–50:1 (9 examples). The cyclized indole products were typically isolated in more than 70% yield and in up to 93% yield, typically with more than 90% ee and in up to 97% ee, and trans/cis ratios of 12:1–28:1 (15 examples). (Figure presented.).
Iridium-catalyzed enantioselective hydrogenation of unsaturated heterocyclic acids
Song, Song,Zhu, Shou-Fei,Pu, Liu-Yang,Zhou, Qi-Lin
, p. 6072 - 6075 (2013/07/05)
Spiral binding: A highly enantioselective hydrogenation of unsaturated heterocyclic acids has been developed by using chiral iridium/spirophosphino oxazoline catalysts (see scheme; BArF-=tetrakis[3,5- bis(trifluoromethyl)phenyl]borate, Boc=tert-butoxycarbonyl). This reaction provided an efficient method for the preparation of optically active heterocyclic acids with excellent enantioselectivities. Copyright
