4176-17-4Relevant articles and documents
Stereoselective Csp3?Csp2 Cross-Couplings of Chiral Secondary Alkylzinc Reagents with Alkenyl and Aryl Halides
Skotnitzki, Juri,Kremsmair, Alexander,Keefer, Daniel,Gong, Ye,de Vivie-Riedle, Regina,Knochel, Paul
, p. 320 - 324 (2019/11/26)
We report palladium-catalyzed cross-coupling reactions of chiral secondary non-stabilized dialkylzinc reagents, prepared from readily available chiral secondary alkyl iodides, with alkenyl and aryl halides. This method provides α-chiral alkenes and arenes with very high retention of configuration (dr up to 98:2) and satisfactory overall yields (up to 76 % for 3 reaction steps). The configurational stability of these chiral non-stabilized dialkylzinc reagents was determined and exceeded several hours at 25 °C. DFT calculations were performed to rationalize the stereoretention during the catalytic cycle. Furthermore, the cross-coupling reaction was applied in an efficient total synthesis of the sesquiterpenes (S)- and (R)-curcumene with control of the absolute stereochemistry.
A asymmetric catalytic synthesis (S)- aryl curcumene method
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, (2017/08/25)
The invention discloses a method for asymmetrically catalyzing and synthesizing (S)-curcumene. According to the method, racemization 2-halogenated propionate ester serves as a starting material, under the catalysis of bis oxazoline/ cobalt, an asymmetrica
Asymmetric synthesis of (R)-ar-curcumene, (R)-4,7-dimethyl-l-tetralone, and their enantiomers via cobalt-catalyzed asymmetric Kumada cross-coupling
Wu, Lin,Zhong, Jiang-Chun,Liu, Shi-Kuo,Liu, Fei-Peng,Gao, Zi-Dong,Wang, Min,Bian, Qing-Hua
, p. 78 - 83 (2015/12/31)
An efficient and concise asymmetric synthesis of (R)-(+)-ar-curcumene, (R)-4,7-dimethyl-l-tetralone, and their enantiomers was accomplished. The key step to construct the stereogenic benzylmethyl centers of these natural products is the cobalt-catalyzed a
