Chiral phosphine-phosphoramidite ligands for highly enantioselective hydrogenation of N-arylimines
作者:Qing Li、Chuan-Jin Hou、Xiao-Ning Liu、De-Zhi Huang、Yan-Jun Liu、Rui-Feng Yang、Xiang-Ping Hu
DOI:10.1039/c4ra16062b
日期:——
The asymmetrichydrogenation of N-arylimines with the chiral phosphine-phosphoramidite ligand, (Sc,Sa)-PEAPhos 2b, has been developed. The results revealed that the presence of the substituents on the 3,3′-positions of the binaphthyl backbone significantly improved the enantioselectivity. The utility of this methodology was demonstrated in the synthesis of the chiral fungicide (R)-metalaxyl.
Chiral Phosphine–Phosphoramidite Ligands for Highly Efficient Ir-Catalyzed Asymmetric Hydrogenation of Sterically Hindered <i>N</i>-Arylimines
作者:Chuan-Jin Hou、Ya-Hui Wang、Zhuo Zheng、Jie Xu、Xiang-Ping Hu
DOI:10.1021/ol301618r
日期:2012.7.6
A mild and general iridium-catalyzed, highly enantioselective hydrogenation of sterically hindered N-arylimines with a new H8-BINOL-derived phosphine–phosphoramiditeligand has been developed. The present catalytic system features high turnover numbers (up to 100000) and good to perfect enantioselectivities (up to 99% ee) for the hydrogenation of a variety of sterically hindered N-arylimines.
Acyl anilines are disclosed having the formula ##STR1## wherein R and R.sup.1 (like or unlike each other)=H; CH.sub.3 ; C.sub.2 H.sub.5 ; n.C.sub.3 H.sub.7 ; --CH.sub.2 --CH.dbd.CH.sub.2 ; --CH.dbd.CH--CH.sub.3 ; R.sup.3 and R.sup.4 (like or unlike each other)=H; alkyl C.sub.1 -C.sub.3 ; halomethyl; Cl; F; CN; O-alkyl; S-alkyl; alkoxymethyl; or R.sup.3 and R.sup.4 together are (CH.sub.2 .dbd.) ##STR2## (R.sup.9 =alkyl C.sub.1 -C.sub.3); CN; --CH(OR.sup.5).sub.2 (R.sup.5 =alkyl or alkylidene ); ##STR3## (R.sup.6 and R.sup.7 =H, alkyl) `n=0,1 Z=phenyl optionally substituted; ##STR4## And R.sup.2 =H, CH.sub.3 ; m=1,2; Y=alkynyl C.sub.2 -C.sub.8 ; phenyl optionally substituted; phenyl-acetyl; furyl, thienyl; pyridyl; heterocyclic groups containing 2 or 3 heteroatoms, one of them different from nitrogen; R.sup.8 =CH.sub.3 ; alkoxymethyl; halomethy; O-alkyl. The compounds of formula I are endowed with a high fungicidal activity and with a low phytotoxicity.