Consecutive reaction of the optically active aminobutyric acid (I) with the sulfonyl chloride (II) and the borane - tetrahydrofuran complex (III) yields the oxazaborolidine (IV) which is employed as a chiral catalyst in the cycloaddition of 2,3-dimethyl-1,3-butadiene (V) with methacrolein (VI...
Catalytic asymmetric homo-aldol reaction of pyruvate-a chiral Lewis acid catalyst that mimics aldolase enzymes. Juhl, K,Gathergood, N,J (?)rgensen, K. A. Chemical Communications . 2000Juhl et al., " Catalytic asymmetric homo-aldol reaction of pyruvate—a chiral Lewis acid catalyst that mimics...
• Shibasaki has developed a catalysed that contains a Lewis acid which activates enones within a chiral environment by co-ordination • The catalyst also contains a Brønsted base to form the nucleophile O OEt O O O La O O O
L-pipecolinic acid derived Lewis base organocatalyst for asymmetric reduction of N-aryl imines by trichlorosilane: effects of the side amide group on catalytic performances[J]. Organic & Biomolecular Chemistry, 2013, 11: 787. CHEN L, WANG C, ZHOU L, et al. Chiral 2, 3-disubstituted ...
(1) through an inverse-electron-demand hetero-Diels–Alder (HDA) reaction. We reasoned that when a chiral Lewis acid catalyst is applied to activate the unsaturated ketone ester (1) through chelation with the two carbonyl groups, chiral azides might be generated by a catalytic asymmetric ...
Enantioselective direct Aldol-type reaction of azlactone via protonation of vinyl ethers by a chiral Brønsted acid catalyst. J. Am. Chem. Soc. 131, 3430–3431 (2009). Article CAS PubMed Google Scholar Zhang, Q-W. et al. Brønsted acid catalyzed enantioselective semipinacol rearrangement ...
a, Chiral dirhodium catalysts widely used for asymmetric nitrene/carbene transfer reactions and Lewis acid catalysis. b, Chiral Rh–Bi catalyst used for asymmetric carbene transfer reactions. c, This work: chiral diruthenium catalysts used for asymmetric C–H amination, cyclopropanation and HDA reactio...
Boosting enantioselectivity of chiral organocatalysts with ultrathin two-dimensional metal–organic framework nanosheets. J. Am. Chem. Soc. 141, 17685–17695 (2019). Article CAS PubMed Google Scholar Makam, P. et al. Single amino acid bionanozyme for environmental remediation. Nat. Commun. 13...
et al., "Br.o slashed.nsted Acid Assisted Chiral Lewis Acid (BLA) Catalyst for Asymmetric Diels-Alder Reaction", J. Am. Chem. Soc., 116(4):1561-1562 (1994). Ishihara, K. et al., "A New Powerful and Practical BLA Catalyst for Highly Enantioselective Diels-Alder Reaction: An ...
and may be in the form of an acid addition salt. In the reactions described herein, the catalyst used is either an acid addition salt of compound (IIA) or (IIB), or an acid is added to the reaction mixture to serve as a co-catalyst for compound (IIA) or (IIB) in electronically ...