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Tropylium-promoted prenylation reactions of phenols in continuous flow


2-Dimethylchroman framework occurs in many complex natural and synthetic compounds which show various types of biological activities such as antitumor, anticancer, antihypertensive, antioxidant and antithrombotic. Herein, we report an organocatalytic approach to the synthesis of 2,2-dimethylchromans where tropylium tetrafluoroborate was used as an organic Lewis acid catalyst for metal-free prenylation reactions of phenols. This method was amenable to continuous flow chemistry to enable an inexpensive pathway to access 2,2-dimethylchromans on multiple-gram scale with short reaction times, high efficiencies and simple product purification.

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The authors acknowledge the Australian Research Council (grant FT180100260) for financial support.

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Correspondence to Thanh Vinh Nguyen.

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Omoregbee, K., Luc, K.N.H., Dinh, A.H. et al. Tropylium-promoted prenylation reactions of phenols in continuous flow. J Flow Chem 10, 161–166 (2020).

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