Metal-Triflate-Catalyzed Synthesis of Polycyclic Tertiary Alcohols by Cyclization of γ-Allenic Ketones
作者:Ilhem Diaf、Gilles Lemière、Elisabet Duñach
DOI:10.1002/anie.201310724
日期:2014.4.14
It has been established that bismuth(III) triflate catalyzes the cyclization of γ‐allenic ketones under mild reaction conditions. This reaction allows the selective formation of polycyclic tertiary alcohols from cyclic ketone derivatives. The resulting dienols can engage in stereoselective cycloadditions to efficiently afford complex polycyclic systems.
Organocatalytic Enantioselective Conjugate Addition to Alkynones
作者:Marco Bella、Karl Anker Jørgensen
DOI:10.1021/ja0493594
日期:2004.5.1
The first catalytic enantioselectiveaddition of beta-dicarbonyl compounds to alkynones is presented. The conjugateaddition proceeds in very high yields, giving a mixture of (Z)- and (E)-enones with up to 95% ee using the cinchona alkaloid [DHQ]2PHAL (5 mol %) as the catalyst. This organocatalyticenantioselective reaction has been further developed to a one-pot procedure to give the optically active
A novel library of chiral guanidines featuring a tartaric acid skeleton was developed from diethyl L-tartrate. These guanidines are easily accessed with tunable style and electronic properties. The utilities of the guanidines were highlighted by their ability to catalyze the alpha-hydroxylation of beta-ketoesters and beta-diketones with remarkable efficiency and excellent enantioselectivity.