Synthesis of diamino carboxylic esters by palladium-catalyzed oxidative intramolecular diamination of acrylates
Synthesis of diamino carboxylic esters by palladium-catalyzed oxidative intramolecular diamination of acrylates
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DOI：
10.1002/asia.200800148
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发表时间：
2008-01-01
影响因子：
4.1
通讯作者：
Hovelmann, Claas H.
中科院分区：
文献类型：
--
作者：
Muniz, Kilian;Streuff, Jan;Hovelmann, Claas H.
未配位的钯（II）盐催化丙烯酸酯的氧化二胺化以产生2，3-二氨基羧酸酯。该反应采用溴化铜（II）作为氧化剂，并进行良好的优异的立体选择性和完全的化学选择性。初步的机理研究提供了证据的直接胺化的C-Pd键的α位置相对于酯基的参与。该方案显着拓宽了钯催化烯烃二胺化的整体范围，并代表了官能化非末端底物的第一次直接二胺化。该反应容易地产生保护的2，3-二氨基酸衍生物，其可以被认为是用于后续合成的高度官能化的结构单元。使用这些新的二胺化产品作为一个合适的起始材料在一个简短的合成生物碱absouline作为一个例子。
Unligated palladium(II) salts catalyze the oxidative diamination of acrylic esters to yield 2,3-diamino carboxylic esters. The reaction employs copper(II) bromide as oxidant and proceeds with good to excellent stereoselectivities and complete chemoselectivity. Preliminary mechanistic studies provide evidence for the involvement of a direct amination of the C-Pd bond in the alpha position relative to the ester group. This protocol significantly broadens the overall scope of the palladium-catalyzed diamination of alkenes and represents the first direct diamination of functionalized nonterminal substrates. The reaction yields readily protected 2,3-diamino acid derivatives, which can be considered as highly functionalized building blocks for subsequent synthesis. The use of one of these new diamination products as a suitable starting material in a short synthesis of the alkaloid absouline is demonstrated as an example.