<i>C</i><sub>2</sub>-Symmetric Chiral Bisoxazolines as Hydrogen-Bond-Acceptor Catalysts in Enantioselective Aldol Reaction of β-Carbonyl Acids with Trifluoroacetaldehyde Hemiacetals
作者:Zhen-Yan Yang、Jun-Liang Zeng、Nan Ren、Wei Meng、Jing Nie、Jun-An Ma
DOI:10.1021/acs.orglett.6b03256
日期:2016.12.16
C2-symmetric chiral bisoxazoline is demonstrated to use hydrogen bonding to catalyze an important family of aldolreactions of trifluoroacetaldehyde hemiacetals with various β-carbonyl acids. This reaction is highly enantioselective, delivering chiral nonracemic trifluoromethylated alcohols with excellent optical purity and good isolated yields. This concept of relaying chiral information via a chiral hydrogen-bond
The magnesium complex (1) has been found to undergo fixation of carbondioxide and the resulting 1-carboxylato-complex (2) transfers the carboxylato group to active methylene compounds (3) including acetophenone, benzylideneacetone, β-ionone, and S-benzyl thioacetate, under mild conditions.
MATSUMURA NOBORU; YAGYU YOSHIO; IMOTO EIJI, NIXON KAGAKU KAJSI, NIRRON KAGAKU KAISNI, J. CHEM. SOS. JAR., CHEM. AND I+
作者:MATSUMURA NOBORU、 YAGYU YOSHIO、 IMOTO EIJI
DOI:——
日期:——
Copper-Catalyzed One-Pot Denitrogenative-Dehydrogenative-Decarboxylative Coupling of β-Ketoacids with Trifluorodiazoethane: Facile Access to Trifluoromethylated Aldol Products
作者:Heng-Ying Xiong、Zhen-Yan Yang、Zhen Chen、Jun-Liang Zeng、Jing Nie、Jun-An Ma
DOI:10.1002/chem.201403073
日期:2014.7.1
novel copper‐catalyzed one‐pot cross‐coupling of β‐ketoacids with in situ generated trifluorodiazoethane has been developed. This reaction provides a direct and efficient method, in which one CC bond and one CO bond were formed in a carbenoid center with concomitant denitrogenation–dehydrogenation–decarboxylation, to afford trifluoromethylatedaldolproducts. In several preliminary experiments, good