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首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Solid-phase synthesis of chiral 3,4-diazaphospholanes and their application to catalytic asymmetric allylic alkylation.
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Solid-phase synthesis of chiral 3,4-diazaphospholanes and their application to catalytic asymmetric allylic alkylation.

机译：手性3,4-二氮杂膦酸酯的固相合成及其在催化不对称烯丙基烷基化中的应用。

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摘要

Functionalized chiral diazaphospholanes ligate to a variety of transition metals, yielding chiral, catalytically active, metal complexes. Previous work has established that amino acid derivatization of the carboxyl groups of (R,R)-N,N'-phthaloyl-2,3-(2-carboxyphenyl)-phenyl-3,4-diazaphospholane (1) yields phosphines that are excellent ligands for palladium-catalyzed asymmetric allylic alkylation reactions. Alanine functionalization is particularly effective for allylic alkylation of 1,3-dimethylallyl acetate. Standard Merrifield resins and amino acid coupling methods are used to synthesize the bead-attached phosphine having the topology bead-linker-LAla-(R,R)-1-LAla-OMe, as a 1:1 mixture of linkage isomers. Use of this supported phosphine in Pd-catalyzed asymmetric allylic alkylation yields 92% enantiomeric excess, matching prior solution-phase results. A 20-member collection of amino acid-functionalized phosphines on beads with the topology bead-linker-AA(2)-AA(1)-1-AA(1)-AA(2) was synthesized by using parallel solid-state methods and screened for efficacy in allylic alkylation. Resulting enantioselectivities indicate that the AA(1) position has the strongest effect on the reaction. Catalyst activities can vary widely with the nature of the phosphine ligand and the reaction conditions. Meaningful analysis of intrinsic catalytic activities awaits identification of the structure and abundance of the active catalyst.
机译：功能化的手性二氮杂膦酸酯连接多种过渡金属，生成手性，催化活性的金属络合物。先前的工作已经确定，（R，R）-N，N'-邻苯二甲酰基-2,3-（2-（2-羧基苯基）-苯基-3,4-二氮杂膦烷（1）的羧基进行氨基酸衍生处理可生成以下膦：钯催化的不对称烯丙基烷基化反应的优良配体。丙氨酸官能化对于1，3-二甲基烯丙基乙酸酯的烯丙基烷基化特别有效。使用标准Merrifield树脂和氨基酸偶联方法合成具有拓扑珠连接子-LAla-（R，R）-1-LAla-OMe拓扑结构的1：1混合物的连接珠的膦。在钯催化的不对称烯丙基烷基化反应中使用这种负载的膦可产生92％的对映体过量，与先前的溶液相结果相符。通过使用并行固态方法合成了具有拓扑结构的珠-连接子-AA（2）-AA（1）-1-AA（1）-AA（2）的珠上的氨基酸官能化膦的20人集合。并筛选了烯丙基烷基化的功效。产生的对映选择性表明，AA（1）位置对反应的影响最大。催化剂的活性可以随膦配体的性质和反应条件而变化。固有催化活性的有意义的分析正在等待鉴定活性催化剂的结构和丰度。

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