Enantioselective Additions of Stabilized Carbanions to Imines Generated from α-Amido Sulfones By Using Lipophilic Salts of Chiral Tris(1,2-diphenylethylenediamine) Cobalt(III) Trications as Hydrogen Bond Donor Catalysts
作者:Hemant Joshi、Subrata Ghosh、John Gladysz
DOI:10.1055/s-0036-1590502
日期:2017.9
S)-dpen)3]3+ 2Cl–BArf20 – [BArf20 – = B(C6F5)4 –] is similarly applied to additions of nitroalkanes (four examples, 89–93% isolated yields, 79–91% ee). Precautions to exclude air or moisture are unnecessary. The enantiopure salt ∆-[Co((S,S)-dpen)3]3+ 2Cl–BArf – [BArf = B(3,5-C6H3(CF3)2)4] is an effective hydrogen bond donor catalyst (10 mol%, r.t., CH2Cl2) for enantioselective additions of dialkyl malonates
作为有机合成中的专题钴的一部分出版 抽象的 对映纯盐∆- [Co((S,S)-dpen)3 ] 3+ 2Cl – BAr f – [BAr f = B(3,5-C 6 H 3(CF 3)2)4 ]是有效的氢键供体催化剂(10 mol%,rt,CH 2 Cl 2),用于在K 2 CO 3(十)存在下,将丙二酸二烷基酯对映选择性地加成自砜[ArCH(SO 2 Ph)NHBoc]生成的Boc衍生的芳亚胺例如91-97%的孤立产量,87-99%ee)。非对映异构体盐Λ-[Co((S,S)-dpen)3 ] 3+ 2Cl – BAr f20 – [BAr f20 – = B(C 6 F 5)4 – ]类似地用于添加硝基烷烃(四个例子,分离产率为89–93%,79 –91%ee)。没有必要排除空气或湿气的预防措施。 对映纯盐∆- [Co((S,S)-dpen)3 ] 3+ 2Cl – BAr f –