Scalable Synthesis for Porous Organic Cages

Abstract

We describe an improved synthesis for a [4 + 6] imine-linked cage, which was shown recently to exhibit microporosity in the crystalline state and which can be converted by recrystallization to produce either porous or nonporous polymorphs. The original methodology for the synthesis of this molecule resulted in poor yields (approximately 35%). Here, we demonstrate that the cage can be prepared in almost 100% yields and can be isolated with high chemical purity.

Keywords:

• Cage
• imine
• microporous

ACKNOWLEDGMENTS

We thank the Centre for Materials Discovery for use of the facilities. We thank the North West Development Agency (UK) and Knowledge Centre for Materials Chemistry for funding (D. P. L.). A. I. C. holds a Royal Society Wolfson Research Merit Award.

Notes

^a Total final volume of reaction mixture after addition of aldehyde solution (400 mL). In all cases, a molar ratio of aldehyde/amine of 1:1.5 was used.

^a Total final volume of reaction mixture after addition of aldehyde solution (ratio of aldehyde solution to amine solution = 4:3). In all cases, a molar ratio of aldehyde/amine of 1:1.5 was used.