3-Amino- and 3-acylamido-2-phosphonopyridines: synthesis by Pd-catalyzed P–C coupling, structure and conversion to pyrido[b]-anellated PC–N heterocycles
作者:Mohamed Shaker S. Adam、Olaf Kühl、Markus K. Kindermann、Joachim W. Heinicke、Peter G. Jones
DOI:10.1016/j.tet.2008.06.010
日期:2008.8
4a to the novel pyrido[b]-anellated 1,3-azaphosphole 5a. Reaction of amidophosphonates 2b–f with LiAlH4 did not result in the expected reductive cyclization, as shown by closely related anilido-2-phosphonates, but led to product mixtures containing N-secondary 3-amino-2-phosphinopyridines 3b–f as the main or major component. The conversion of 3b,d,e with DMFA to 5b,d,e provides first examples of N-substituted
钯催化的3-氨基和3-酰氨基-2-溴吡啶的交叉偶联1A - ˚F与亚磷酸三乙酯的允许3-氨基和3-酰氨吡啶-2-膦酸二酯的合成2A - ˚F,而镍催化剂虽然可以提供相关的苯胺基-2-膦酸酯,但被证明是无活性的。用LiAlH 4还原氨基膦酸酯2a,得到3-氨基-2-膦基吡啶(3a),将其与二甲基甲酰胺二甲基乙缩醛(DMFA)经由磷烯烃中间体4a环缩合为新型吡啶并[ b ]取代的1,3-氮杂磷腈5a。。amidophosphonates的反应2B - ˚F用的LiAlH 4并没有导致在预期还原环合,如由密切相关的酰苯胺-2-膦示出,但导致了含有产物的混合物Ñ -secondary 3-氨基-2- phosphinopyridines 3B - ˚F作为主要或主要组成部分。的转化率图3b,d,ê用DMFA至图5b,d,È提供的第一实施例ñ -取代的吡啶并[ b ] -anellated azap