Phosphorus-Based Functional Groups as Hydrogen Bonding Templates for Rotaxane Formation

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• 作者：Rehan Ahmed ; Andrea Altieri ; Daniel M. D鈥橲ouza ; David A. Leigh ; Kathleen M. Mullen ; Marcus Papmeyer ; Alexandra M. Z. Slawin ; Jenny K. Y. Wong ; J. Derek Woollins
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：August 10, 2011
• 年：2011
• 卷：133
• 期：31
• 页码：12304-12310
• 全文大小：989K
• 年卷期：v.133,no.31(August 10, 2011)
• ISSN：1520-5126

文摘

We report on the use of the hydrogen bond acceptor properties of some phosphorus-containing functional groups for the assembly of a series of [2]rotaxanes. Phosphinamides, and the homologous thio鈥?and selenophosphinamides, act as hydrogen bond acceptors that, in conjunction with an appropriately positioned amide group on the thread, direct the assembly of amide-based macrocycles around the axle to form rotaxanes in up to 60% yields. Employing solely phosphorus-based functional groups as the hydrogen bond accepting groups on the thread, a bis(phosphinamide) template and a phosphine oxide鈥損hosphinamide template afforded the corresponding rotaxanes in 18 and 15% yields, respectively. X-ray crystallography of the rotaxanes shows the presence of up to four intercomponent hydrogen bonds between the amide groups of the macrocycle and various hydrogen bond accepting groups on the thread, including rare examples of amide-to-phosphinamide, -thiophosphinamide, and -selenophosphinamide groups. With a phosphine oxide鈥損hosphinamide thread, the solid-state structure of the rotaxane is remarkable, featuring no direct intercomponent hydrogen bonds but rather a hydrogen bond network involving water molecules that bridge the H-bonding groups of the macrocycle and thread through bifurcated hydrogen bonds. The incorporation of phosphorus-based functional groups into rotaxanes may prove useful for the development of molecular shuttles in which the macrocycle can be used to hinder or expose binding ligating sites for metal-based catalysts.