Ortho-allylation of 1-arylpyrazoles with allyl phenyl ether via iron-catalyzed C-H bond activation under mild conditions
Date of Issue2014
School of Physical and Mathematical Sciences
An iron salt and a bipyridine-type ligand catalyze the ortho-allylation of 1-arylpyrazoles and congeners with allyl phenyl ether under mild conditions (0 °C). The ligand, an organozinc base, and the nature of the allylating reagent are crucial for the success of this reaction. Under these conditions, a competitive phenylation reaction is largely retarded, and cross-coupling of the organozinc with the allyl electrophile is minimized. The reaction may proceed via iron-catalyzed ortho C[BOND]H activation to form a metallic intermediate, which then reacts with the allyl ether in a γ selective fashion.
Advanced synthesis & catalysis
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