Chiral 8-Amino-5,6,7,8-tetrahydroquinoline Derivatives in Metal Catalysts for the Asymmetric Transfer Hydrogenation of 1-Aryl Substituted-3,4-dihydroisoquinolines as Alkaloids Precursors
作者:Giorgio Facchetti、Francesca Neva、Giulia Coffetti、Isabella Rimoldi
DOI:10.3390/molecules28041907
日期:——
Although modest enantiomeric excess values were obtained (up to 69% ee in the case of substrate I), a satisfactory quantitative conversion was successfully fulfilled even in the case of the most demanding hindered substrates when La(OTf)3 was used as beneficial additive, opening up the possibility for a rational design of novel chiral catalysts alternatives to the Noyori-Ikariya (arene)Ru(II)/TsDPEN
基于 8-氨基-5,6,7,8-四氢喹啉主链的手性二胺,称为 CAMPY (L1),或 2-甲基取代的类似物 Me-CAMPY (L2),被用作 Cp* 金属配合物中的新型配体对于一系列取代的二氢异喹啉 (DHIQ) 的 ATH,已知是合成生物活性生物碱的关键中间体。在这种反应中评估了不同的金属基配合物,铑催化剂 C3 和 C4,证明在反应性和对映选择性方面都是最有效的。尽管获得适度的对映体过量值(在底物 I 的情况下高达 69% ee),但当 La(OTf)3 用作有益添加剂时,即使在要求最苛刻的受阻底物的情况下,也成功实现了令人满意的定量转化,