121378-13-0Relevant articles and documents
Enantioselective conjugate addition of cyanide to chalcones catalyzed by a magnesium-Py-BINMOL complex
Dong, Cheng,Song, Tao,Bai, Xing-Feng,Cui, Yu-Ming,Xu, Zheng,Xu, Li-Wen
, p. 4755 - 4759 (2015)
An enantioselective magnesium-catalyzed conjugate addition of trimethylsilyl cyanide to chalcones in the presence of Py-BINMOL with multiple stereogenic centers, through dual activation of substrates, has been successfully developed with moderate to good enantioselectivities and in good yields.
Highly efficient asymmetric conjugate hydrocyanation of aromatic enones by an anionic chiral phosphate catalyst
Wang, Yao-Feng,Zeng, Wei,Sohail, Muhammad,Guo, Jiyi,Wu, Shaoxiang,Chen, Fu-Xue
, p. 4624 - 4633 (2013/07/26)
Chiral keto nitriles (β-cyano ketones) have been prepared by a facile and efficient asymmetric conjugate hydrocyanation of poorly active chalcone-type enones with benzophenone cyanohydrin. Using in situ generated 5-10 mol-% of sodium (S)-6,6′-di(1-adamantyl)-1,1′-binaphthyl-2,2′-diyl phosphate as catalyst and 5-10 mol-% of 2-tert-butylphenol as an additive, high yields and excellent enantioselectivities were obtained within 2 h in toluene at 80 °C. The development of catalysts, optimization of the reaction parameters, and substrate scope are reported. On the basis of the experimental results, HCN is shown to be the real cyanide source and a mechanism is proposed to explain the origin of the enantioselectivity with the chiral-anion-modified nucleophile HCN. The asymmetric conjugate hydrocyanation of poorly reactive chalcone-type enones with benzophenone cyanohydrin using an anionic chiral phosphate catalyst has been achieved in high yields (72-96 %) and excellent enantioselectivities (92-98 % ee). It is proposed that the chiral anion modifies HCN, the real nucleophile, in the transition state through hydrogen bonding. Copyright
Enanthioselective Phase-Transfer Catalysis by Optically Active Crown Ethers
Dehmlow, Eckehard V.,Sauerbier, Christiane
, p. 181 - 186 (2007/10/02)
1,2-Bis(hydroxymethyl)-15-crown-5 (1a), its dibenzyl ether (1b), and a series of esters with substituted benzoic acid (3) were probed as enanthioselective phase-transfer catalysts.Optical yields were observed in epoxidations of unsaturated ketones by hypochlorite and in cyanide additions to such compounds.The maximum ee value was 45percent.Polar side groups of the optically active crown ethers proved to be vital for enanthiomeric excesses.