Thorpe reactions scope

Recently, Chirik s group reported an iron-catalyzed [2 + 2]-cycloaddition process with a,co-dienes (Scheme 9.23) [50]. The tridentate pyridine-diimine complex 31 gave excellent conversions with a short reaction time (TOF>240h-1) and a broad substrate scope is accepted by the catalyst. Esters, amides, amines and even 1,6-heptadiene can be used as substrates without requiring the Thorpe-Ingold effect. 

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