A new class of chiral C-2-symmetric N-donor pincer ligands, 2,5-bis (2-oxazolinylclimethylmethyl)pyrroles (PdmB ox)H, was synthesized starting from the readily available ethyl 2,2-dimethyl-3-oxobutanoate (1); The synthesis of the ligand backbone was achieved by oxidative enole coupling with CuCl2 followed by Paal-Knorr-type pyrrole synthesis. The corresponding protioligands ((R)PdmBox)H (R = iPr: 5a;,Ph: 5b) were obtained by condensation with amino alcohols and subsequent zinc-catalyzed cyclization. Reaction of the lithiated, ligands with [NiCl2(dme)] yielded the corresponding square-planar nickel(II) complexes [((R)PdmBox)NiCl] (6a/b). Salt metathesis of 6a with the corresponding alkali or cesium salts in acetone led to the formation of air-and moisture-stable [((iPr)PTdinBox)NiX] (X = F (7), X = Br (8), X = I (9), X = N-3 (10), X = OAc (11). Furthermore, the conversion of [((iPr)PdmBox)NiF] (7) with hydride transfer reagents such as PhSiH3 led to the stable hydrido species [(iPr)PdmBox)NiH] (27), the stoichiometric transformations of which were studied. Treatment of 6a with organometallic reagents such as ZnEt2, PhLi, PhC=CLi, NsLi, or (Bn-4F)(2)Mg(THF)(2) gave the corresponding alkyl, alkynyl, or aryl complexes. The availability of the new nonisomerizable PdmBox pincer ligands allowed the comparative-study of their ligation to square-planar complexes as helically twisted spectator ligands as opposed to the enforced planar rigidity of their isoPmBox analogues and the way this influences the reactivity of the Ni complexes.