Reactions of nickel(0) with organochlorides, organobromides, and organoiodides: mechanisms and structure/reactivity relationships

Abstract

The reactions of nickel(0) complexes with phosphine, bipyridine-type, and N-heterocyclic carbene ligands with aryl, vinyl, and alkyl halides is reviewed.

Lewis Acid‐Promoted Oxidative Addition at a [Ni0(diphosphine)2] Complex: The Critical Role of a Secondary Coordination Sphere

“…In addition to monodentate phosphines, chelating diphosphine ligands have also been studied, for example [M 0 (diphosphine) 2 ], wherein ligand dissociation results in bent "[M 0 (k 2 -diphosphine)]" or trigonal planar "[M 0 (k 1 -diphosphine)(k 2 -diphosphine)]" complexes that are more reactive than their linear 14-electron "[M 0 (PR 3 ) 2 ]" counterparts (Scheme 1B). [3] Access to such unsaturated complexes is often obstructed by the reluctance of such ligands to dissociate, owing (in part) to the chelate effect. As a point of comparison, as early as 1971, it was shown that the 18-electron fragment, [Pd 0 (dppe) 2 ] (dppe = 1,2-bis(diphenylphosphino)ethane) did not react with aryl halides; [4] this contrasts with [Pd 0 (PPh 3 ) 4 ], which is a textbook precursor for concerted oxidative addition.…”

Stereoconvergent and -divergent Synthesis of Tetrasubstituted Alkenes by Nickel-Catalyzed Cross-Couplings

“…This could potentially be rationalized in terms of a less stable oxidative addition complex 1a'-L2 and potential com-or disproportionation degradation pathways. 86 In addition to the stoichiometric isomerization experiments, product isomerization under both optimized reaction conditions was excluded, as no significant isomerization nor decomposition was detected upon subjecting (Z)-3aa to the (E)-selective conditions C2 nor (E)-3aa to the (Z)-selective conditions C1 (see SI for details). With the accumulated data in hand, transmetalation was extensively investigated using DFT to rationalize the experimentally observed diastereoselectivity.…”

Inhibition of (dppf)nickel-catalysed Suzuki–Miyaura cross-coupling reactions by α-halo-N-heterocycles

“…Our research programme in this field has focussed on developing an understanding of reaction mechanisms and substrate/reactivity relationships in nickel catalysis. 13 We have studied the reactions of aryl 14 and alkyl halides 15 with a prototypical dppf-nickel(0) complex, and established that aryl halide substrates that bear functionality such as aldehydes and ketones exhibit interesting and potentially exploitable behaviour in catalytic reactions. 16,17 We were interested in how the fundamental reactivity of haloheteroarenes with nickel(0) differed from the reactivity of haloarenes, and how this might affect the outcomes of relevant cross-coupling reactions.…”