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Expanded Cyclotetrabenzoins

submitted on 30.07.2020, 16:21 and posted on 31.07.2020, 09:11 by Andrew Eisterhold, Steffen Otterbach, Stefan Bräse, Patrick Weis, Xiqu Wang, Ksenia V. Kutonova, Ognjen Miljanic
Cyclobenzoins are stable and shape-persistent macrocycles which offer promise as components of optoelectronic and porous materials. We report three new cyclotetrabenzoins, derived from biphenyl, naphthalene, and tolane skeletons. Their synthesis relied on the N-heterocyclic carbene-catalyzed benzoin condensation. Isolated as their acetic esters, these compounds are characterized by structures similar in shape, but larger in size than the parent cyclotetrabenzoin. Alkyne groups of the tolane-based cyclotetrabenzoin were post-synthetically functionalized with Co2(CO)6 moieties under mild reaction conditions.


We acknowledge the support from the US National Science Foundation (award DMR-1904998 to O. Š. M.), the Welch Foundation (award E-1768 to O. Š. M.), the donors of the American Chemical Society Petroleum Research Fund (award ND-58919 to O. Š. M.), and the University of Houston. K. V. K. thanks Deutsche Forschungsgemeinschaft (DFG) for funding under Germany’s Excellence Strategy – 2082/1 – 390761711. P. W. thanks the generous funding from the DFG Collaborative Centre SFB/TRR 88 “3MET” (Project C6). O. Š. M. thanks the Max Kade and Alexander von Humboldt Foundations for supporting his summer stay at the Ruprecht-Karls-Universität in Heidelberg (Germany), during which the collaboration that produced these results was initiated.


Email Address of Submitting Author


University of Houston



ORCID For Submitting Author


Declaration of Conflict of Interest