Synthesis of Enantiomerically Enriched Imidazolidin-2-Ones through Asymmetric Palladium-Catalyzed Alkene Carboamination Reactions
作者:Brett A. Hopkins、John P. Wolfe
DOI:10.1002/anie.201205233
日期:2012.9.24
leads to significantly improved enantioselectivities with electron‐poor aryl halide substrates. It is suggested that the CC bond‐forming reductive elimination is the enantiodetermining step in these reactions.
正水效应:由[Pd 2 (dba) 3 ](dba=二亚苄基丙酮)和( S )-Siphos-PE组成的催化剂可有效地将N-烯丙基脲与芳基溴进行对映选择性偶联,得到4-取代咪唑烷- 2个。添加水可显着提高缺电子芳基卤化物底物的对映选择性。表明C → C键形成的还原消除是这些反应中的对映决定步骤。
Gold(I)-Catalyzed Intramolecular Hydroamination of N-Allylic N′-Arylureas to form Imidazolidin-2-ones
作者:Hao Li、Feijie Song、Ross A. Widenhoefer
DOI:10.1002/adsc.201000844
日期:2011.4.18
Treatment of N‐allylic N′‐arylureas with a catalytic 1:1 mixture of di‐tert‐butyl‐o‐biphenylphoshphine gold(I) chloride and silver hexafluorophosphate (1 mol%) in chloroform at room temperature led to 5‐exo‐hydroamination to form the corresponding imidazolidin‐2‐ones in excellent yield. In the case of N‐allylic ureas that possessed an allylic alkyl, benzyloxymethyl, or acetoxymethyl substituent, gold(I)‐catalyzed
Stereoselective synthesis of imidazolidin-2-ones via Pd-catalyzed alkene carboamination. Scope and limitations
作者:Jonathan A. Fritz、John P. Wolfe
DOI:10.1016/j.tet.2008.04.015
日期:2008.7
alkenyl bromides via Pd-catalyzed carboamination reactions is described. The N-allylurea precursors are prepared in one step from readily available allylic amines and isocyanates, and the Pd-catalyzed reactions effect the formation of a C-C bond, a C-N bond, and up to two stereocenters in a single step. Good diastereoselectivities are obtained for the conversion of substrates bearing allylic substituents
Synthesis and application of a new chiral monodentate spiro phosphoramidite ligand based on hexamethyl-1,1′-spirobiindane backbone in asymmetric hydroamination/arylation of alkenes
作者:Huanyu Shan、Rihuang Pan、Xufeng Lin
DOI:10.1039/c8ob01785a
日期:——
The design and synthesis of a new chiral monodentate spiro phosphoramidite ligand based on a hexamethyl-1,1′-spirobiindane scaffold has been accomplished. The ligand could serve as an elegant chiral monodentate ligand in the Pd-catalyzed asymmetric hydroamination/arylation of alkenes leading to chiral imidazolidin-2-ones with good enantioselectivities.
A New Synthesis of Imidazolidin-2-ones via Pd-Catalyzed Carboamination of <i>N</i>-Allylureas
作者:Jonathan A. Fritz、Josephine S. Nakhla、John P. Wolfe
DOI:10.1021/ol060707b
日期:2006.6.1
A new strategy for the preparation of substituted imidazolidin-2-ones in two steps from readily available N-allylamines is described. Addition of the amine starting materials to isocyanates affords N-allylureas, which are converted to imidazolidin-2-one products with generation of two bonds and up to two stereocenters when treated with aryl bromides and catalytic amounts of Pd-2(dba)(3)/Xantphos in the presence of (NaOBu)-Bu-t.