Catalytic Asymmetric Intramolecular Hydroamination of Alkynes in the Presence of a Catalyst System Consisting of Pd(0)-Methyl Norphos (or Tolyl Renorphos)-Benzoic Acid
作者:Meda Narsireddy、Yoshinori Yamamoto
DOI:10.1021/jo801785r
日期:2008.12.19
Renorphos (D), and tolyl Renorphos (E) were synthesized and used as chiral bisphosphine ligands for the catalyst system, Pd(2)(dba)(3) x CHCl(3)/PhCOOH, in an intramolecular hydroamination of aminoalkynes 15. Among the Norphos series, methyl Norphos (A) was the best ligand for the hydroamination, and the corresponding five- and six-membered nitrogen heterocycles 16 were obtained in high yields with high
合成对映体纯的甲基Norphos(A),甲苯基Norphos(B),CF(3)Norphos(C),甲基Renorphos(D)和甲苯基Renorphos(E),并用作催化剂体系Pd(的手性双膦配体) 2)(dba)(3)x CHCl(3)/ PhCOOH,在氨基炔烃的分子内加氢胺化中。15.在Norphos系列中,甲基Norphos(A)是加氢胺化的最佳配体,相应的是5-和6-高收率和高对映选择性地获得了二元氮杂环16。在Renorphos系列中,甲苯基Renorphos(E)的结果最好。甲基Norphos(A)和甲苯基Renorphos(E)均具有高收率和高对映选择性。使用Me-Norphos进行的NMR研究表明,该配体在Pd(2)(dba)(3)存在下逐渐被氧化。即使在使用Ar气氛的条件下,C(6)D(6)中的CHCl(3)仍会生成Me-Norphos氧化物,从而阻止了分子内加氢胺化