Singh Om V, Han Hyunsoo
Department of Chemisry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
Tetrahedron Lett. 2007 Oct 1;48(40):7084-7098. doi: 10.1016/j.tetlet.2007.08.009.
Ir(I)-catalyzed intermolecular allylic amidation of ethyl allylic carbonates with soft nitrogen nucleophiles under completely "salt-free" conditions is described. A combination of Ir(COD)Cl, a chiral phosphoramidite ligand L*, and DBU as a base in THF effects the reaction. The reaction appears to be quite general, accommodating a wide variety of R-groups and soft nitrogen nucleophiles, and proceeds with excellent regio- and enantioselectivities to afford the branched N-protected allylic amines. The developed reaction was conveniently utilized in the asymmetric synthesis of Boc protected alpha- and beta-amino acids as well as (-)-cytoxazone.
描述了在完全“无盐”条件下，铱（I）催化烯丙基碳酸乙酯与软质氮亲核试剂的分子间烯丙基酰胺化反应。[Ir(COD)Cl]₂、手性亚磷酰胺配体L*和DBU在四氢呋喃中作为碱的组合可实现该反应。该反应似乎具有相当的通用性，能兼容多种R基团和软质氮亲核试剂，并以优异的区域选择性和对映选择性进行反应，生成支链N-保护的烯丙基胺。所开发的反应可方便地用于Boc保护的α-和β-氨基酸以及（-）-细胞恶嗪的不对称合成。
