Iridium-catalysed asymmetric allylic substitutions
Iridium-catalysed asymmetric allylic substitutions
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DOI：
10.1039/b614169b
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发表时间：
2007-01-01
影响因子：
4.9
通讯作者：
Weihofen, Robert
中科院分区：
文献类型：
--
作者：
Helmchen, Guenter;Dahnz, Axel;Weihofen, Robert
铱催化的烯丙位取代是对传统钯催化变体的补充。以简单、容易获得的单取代烯丙基乙酸酯和碳酸酯作为底物，Ir催化剂通常有利于手性、支链产物，而Pd催化剂通常产生线性、非手性产物。用亚磷酰胺作为配体，区域选择性> 10：1和对映体过量在95- 99%ee的范围内是目前常规实现的。可以使用宽范围的亲核试剂：例如稳定的碳负离子、胺（包括其磺酰基和二酰基衍生物）、酚盐和醇盐。基于烯丙基取代和闭环复分解的组合的一些应用表明该方法用于合成生物活性化合物的相当大的潜力。
Ir-Catalysed allylic substitution is supplementing the traditional Pd-catalysed variant. With simple, easily available monosubstituted allylic acetates and carbonates as substrates, Ir catalysts generally favour chiral, branched products, while Pd catalysts typically give rise to linear, achiral products. With phosphorus amidites as ligands, regioselectivities > 10 : 1 and enantiomeric excess in the range 95-99 %ee are currently routinely achieved. A broad range of nucleophiles can be employed: for example stabilised carbanions, amines including their sulfonyl- and diacyl-derivatives, phenolates and alkoxides. A few applications, based on combinations of the allylic substitution and ring closing metathesis, indicate considerable potential of the method for the synthesis of biologically active compounds.