Synthesis of the thyroid hormone analog GC-1 via Bi(OTf)3-catalyzed benzylation

Starting from two commercially available phenol derivatives, the thyroid hormone analog, GC-1, was successfully prepared. The strategy featured a convergent coupling of the two halves via the Lewis/Brønsted acid-mediated regioselective Friedel–Crafts-type (FC-type) benzylation to furnish the corresponding diarylmethane core as the key step. Various transition metal triflates were screened as catalysts for this key step, among which Bi(OTf)3 was found to be the most effective.

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