A new type of oxidative addition of an iodoarene to a Pd(II) complex

Abstract

Oxidative addition of N-(2-iodophenyl)formamide to Pd(dba)2 (dba = dibenzylideneacetone) in the presence of 4,4′-ditertbutyl-2,2′-bipyridine (tBubpy) produces [Pd(C6H4NHCHO-2)I(tBubpy)] (1) which inserts 2-iodophenyl isocyanide to give [Pd{C(NC6H4I-2)C6H4NHCHO-2}I(tBubpy)] (2). Dehydroiodination of 2 with Tl(acac) (acacH = acetylacetone) gives the stable Pd(iv) complex OC-6-35-[Pd{C,N,N-C(NC6H4-2)C6H4NCHO-2}I(tBubpy)] (4) likely resulting from the spontaneous oxidative addition of the I-Ar moiety present in the unstable intermediate Pd(ii) complex [Pd{C,N-C(NC6H4I-2)C6H4NCHO-2}(tBubpy)] (3). The crystal structure of 4 shows various C-H⋯O hydrogen bonds resulting in chains of dimers stacked along the a axis.