A stereodynamic phosphoramidite ligand derived from 3,3′-functionalized ortho-biphenol and its rhodium(I) complex

详细信息    查看全文

• 作者：Golo Storch ; Luisa Deberle ; Jan-Michael Menke ; Frank Rominger and Oliver Trapp
• 刊名：Chirality
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：28
• 期：11
• 页码：744-748
• 全文大小：341K
• ISSN：1520-636X

文摘

Stereodynamic ligands and complexes bearing functional groups to attach chiral or achiral binding sites and auxiliaries are highly attractive due to the interesting opportunities for controlling the stereochemical outcome of enantioselective transformations. In this study we report the preparation of a 3,3′-functionalized biphenol (BIPOL) phosphoramidite ligand (P_Am) bearing 3,5-dichlorobenzoyl (3,5-DCB) amide binding sites for noncovalent interactions. Upon coordination to [Rh(COD)₂]BF₄ this substitution pattern directs one of the 3,5-DCB binding sites in close proximity of the metal center resulting in liberation of both COD ligands and the formation of a [Rh(P_Am)₂]BF₄ complex. Coordination of the amide carbonyl unit was found to be reversible, since the complex acted as an active catalyst in the hydrogenation of dehydroamino acid derivatives. X-ray crystallographic investigation revealed that the second 3,5-DCB unit is capable of forming noncovalent π–π interactions connecting both phosphoramidite ligands.