Asymmetric Bio- and Organocatalytic Cascade Reaction - Laccase and Secondary Amine-Catalyzed α-Arylation of Aldehydes

2015 ◽  
Vol 357 (8) ◽  
pp. 1822-1830 ◽  
Author(s):  
Sanel Suljić ◽  
Jörg Pietruszka ◽  
Dennis Worgull
Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 713 ◽  
Author(s):  
Zhe An ◽  
Lifeng Chen ◽  
Yitao Jiang ◽  
Jing He

Heterogeneous synergistic catalysis by SBA-15 immobilized chiral amines catalysts has promoted efficient aza-Michael–Henry tandem reaction for the synthesis of chiral 3-Nitro-1,2-Dihydroquinoline. Final products in the asymmetric aza-Michael–Henry cascade reactions between 2-aminobenzaldehyde and β-nitrostyrolene were afforded in a yield of 85% and an enantiomeric excess (ee) value of 98% on (S)-(–)-2-aminomethyl-1-ethylpyrrolidine immobilized SBA-15. SBA-15-AEP catalyst has been also extended to the asymmetric aza-Michael–Henry cascade reaction of substituted R1-2-aminobenzaldehyde and R2-substituted nitroolefin. The heterogeneous synergistic mechanism for both tertiary amine and secondary amine immobilized mesoporous has been proposed in detail including the geometrical constraints in the ee promotion.


1963 ◽  
Vol 43 (3) ◽  
pp. 345-360 ◽  
Author(s):  
Stanley Kushinsky ◽  
Jane (Wu) Tang

ABSTRACT A convenient and mild procedure is described in this paper whereby free and conjugated oestrogens may be extracted from urine. The extracts containing approximately 90 per cent of the oestrogens are devoid of most of the extraneous material and may be reduced in volume to less than 1/15 of that of the urine. The procedure consists of the following steps: (1) a 10 per cent (v/v) solution of a high molecular weight secondary amine (Amberlite LA-2, Rohm and Haas) in ethyl acetate is washed with formic acid and water, (2) the oestrogens in urine (acidified to pH 2 or 3 with H2SO4) are extracted with the LA-2 solution, (3) the oestrogen fraction is back-extracted from the organic solution with dilute aqueous ammonia.


2020 ◽  
Author(s):  
Rémi Blieck ◽  
Sebastien Lemouzy ◽  
Marc Taillefer ◽  
Florian Monnier

A dual copper/enamine catalytic system is found to enable an intermolecular enantioselective α-addition of various carbonyl nucleophiles to allenamides. Secondary amine catalysts allowed the highly enantioselective addition of aldehydes, while using primary amine catalysts led to the enantioselective addition of ketoester nucleophiles. The process was found to be highly regio-, stereo- and enantio-selective and represented the first allene hydrofunctionalization using an synergistic catalysis involving copper


2020 ◽  
Vol 17 (12) ◽  
pp. 944-950
Author(s):  
Shangrong Zhu ◽  
Xuechen Lu ◽  
Qiuneng Xu ◽  
Jian Li ◽  
Shenghu Yan

A straightforward and efficient synthesis of acridine derivatives via a copper-catalyzed cascade reaction among isoxazoles and diaryliodonium salts is achieved. Various mono-, multi-substituted and 9-substituted acridine derivatives could be obtained in moderate to good yields. The process has gone through tandem double arylation and Friedel-Crafts reactions.


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