Generation of an optically active rhodium(III) complex by crystallization-induced spontaneous resolution of a racemic mixture

Spontaneous resolution, whence and whither: from enantiomorphic solids to chiral liquid crystals, monolayers and macro- and supra-molecular polymers and assemblies

“…For compounds or complexes incorporating a stereogenic centre this can lead to chiral catalysts, as in the spontaneous resolution of an optically active rhodium(III) complex in which the metal ion is coordinated by a chiral phosphate ligand as the source of asymmetry. 63 If an achiral compound crystallises in a chiral structure, or a chiral complex forms from achiral components, then there is the opportunity to perform what has been referred to as ''absolute asymmetric synthesis''. 64 This term is justified because at the start of the process, there are no chiral components, although obviously the chirality comes from the symmetry breaking in the crystal formation which can then be exploited for preparation of optically active compounds.…”

Spontaneous Resolution upon Crystallization and Preferential Induction of Chirality in a Discrete Tetrahedral Zinc(II) Complex Comprised of Achiral Precursors

“…25−27 Subsequently, a few more six-coordinated discrete complexes were reported to undergo spontaneous resolution upon crystallization. 28−32 Lennartson and Håkansson and others have even reported conglomerate crystallization in the case of five, 33−35 eight, 36,37 and nine 38 -coordinated discrete complexes, although four 39 -coordinated discrete chiral complexes containing achiral constituents are scarce. The research group of Enamullah and Janiack first reported spontaneous resolution in the case of a discrete four-coordinated complex, [Rh(Nphenylglycinato)(η 4 -cycloocta-1,5-diene)], which contained the prochiral ligand N-phenylglycine.…”

Novel α-fluorinated cyclic phosphite and phosphinite ligands and their Rh-complexes as suitable catalysts in hydroformylation

“…The X-ray analysis of 6a reported earlier in our preliminary communication [24] has revealed that it crystallizes in the chiral space group (P2 1 2 1 2 1 ) giving the enantiopure crystals (½a D 20 $ 900 (c 1, CHCl 3 )) (Fig. 2).…”

“…The interaction proceeds at an elevated temperature in the absence of any solvent according the procedure described by us earlier for 5a [24] (Scheme 2). The other diethylphosphinite ligand 5b was obtained similarly by the ÔamideÕ procedure in nearly quantitative yield (see Tables 1,2).…”

“…2-chloro-1,3,2-benzodioxaphospholene was obtained by known procedure [29]. For the synthesis of ligand 5a and its Rh III complex 6a, see [24].…”