Modular, Catalytic Enantioselective Construction of Quaternary Carbon Stereocenters by Sequential Cross-Coupling Reactions
作者:Bowman Potter、Emma K. Edelstein、James P. Morken
DOI:10.1021/acs.orglett.6b01580
日期:2016.7.1
chiral γ,γ-disubstituted allylboronates in the presence of RuPhos ligand occurs with high regioselectivity and enantiospecificity, furnishing nonracemic compounds with quaternary centers. Mechanistic experiments suggest that the reaction occurs by transmetalation with allyl migration, followed by rapid reductive elimination.
Entrapment of a chiral cobalt complex within silver: a novel heterogeneous catalyst for asymmetric carboxylation of benzyl bromides with CO<sub>2</sub>
作者:Heng-Pan Yang、Ying-Na Yue、Qi-Long Sun、Qiu Feng、Huan Wang、Jia-Xing Lu
DOI:10.1039/c5cc04554a
日期:——
A novel way to accommodate heterogeneous catalysis, CO2fixation and asymmetric synthesis on one catalyst is reported.
报道了一种新颖的方法,可以在一个催化剂上实现异质催化、CO₂固定和不对称合成。
Catalytic Asymmetric Synthesis Using Feedstocks: An Enantioselective Route to 2-Arylpropionic Acids and 1-Arylethyl Amines via Hydrovinylation of Vinyl Arenes
作者:Craig R. Smith、T. V. RajanBabu
DOI:10.1021/jo900198b
日期:2009.4.17
been developed. Excellent yields (>97%), regioselectivities (>99%), and enantioselectivities (>97% ee) for the desired branched products were obtained in the asymmetrichydrovinylationreactions of vinyl arenes, and the products from these reactions were transformed into 2-arylpropionic acids via oxidative degradation. Subsequent Curtius or Schmidt rearrangements of these acids provided highly valued 1-arylethyl
Phosphonate-Directed Catalytic Asymmetric Hydroboration: Delivery of Boron to the More Substituted Carbon, Leading to Chiral Tertiary Benzylic Boronic Esters
作者:Suman Chakrabarty、James M. Takacs
DOI:10.1021/acscatal.8b03591
日期:2018.11.2
boronic esters. Hydroboration is catalyzed by a chiral rhodium catalyst prepared in situ from a Rh(I) precursor in combination with a simple TADDOL-derived chiral cyclic monophosphite in a 1:1 ratio. The regio- and stereochemistry arise from the combined effects of the relative disposition of the directing group to the alkene, the alkene substitution pattern, and the necessity of an arylsubstituent attached
Synthesis and photochemistry of (2S,4R)- and (2S,4R)-1,2,3,4-tetrahydro-4-ethyl-1,1,4-trimethyl-3Z-ethylidene-2-naphthalenols
作者:F. W. A. M. Miesen、J. L. J. van Dongen、E. W. Meijer
DOI:10.1002/recl.19941130602
日期:——
formation of hydroperoxide 13 and epoxy alcohol 15a, which hydrolyses on standing to triol 16a. The observed stereochemistry is explained by the stereoselective coordination of the hydroxyl group at the chiral allylic site with the attacking electrophilic oxygen. In the case of 11a a more complicated reaction mixture was obtained in which, analogously, the epoxy alcohol 15b and triol 16b were present. Semi-empirical