Enantiomeric enrichment of a nonracemic conglomerate of a chiral oxo-rhenium(v) complex

Asymmetric autocatalysis: crystallization-induced highly enantioselective synthesis of a conglomerating oxo-rhenium(V) complex

“…[50][51][52] The cis-with trans-equilibrium reported in those papers is further discussed here in connection with three precursor reactions used to make the desired equilibrating rhenium complex. We focus on the synthesis, illustrated in Scheme 1, of chiral cis-ReOCl 2 (P $ O)py cis-1 as a conglomerate of C-(+) 589 and A-(À) 589 enantiomers, which can be accomplished from optically inactive substrates in several ways.…”

Effect of a methyl group on the spontaneous resolution of a square-pyramidal coordination compound: crystal packing and conglomerate formation

“…Compound 1: (Yield: A moderately strong and sharp peak due to the N-H stretching vibration at 3233 (1), and 3187 cm 21 (2) indicates that the imine double bond of the Schiff base has been reduced. The strong bands at 1650 and 1658 cm 21 are likely to be due to the antisymmetric stretching mode of the carboxylate group, whereas the bands at 1358 and 1347 cm 21 can be attributed to the symmetric stretching modes of the carboxylato ligands in 1 and 2, respectively.…”

“…The interaction energy of the assembly (depicted in Fig. 11) at the B97-D/SVP level of theory amounts to 2120.6 kcal mol 21 . As shown in Fig.…”

“…When the (green) methyl groups are replaced by hydrogen atoms (i.e. when L 2 is changed to L 1 ), the interaction energy for the dimer is 235.1 kcal mol 21 , therefore suggesting that the formation of the hydrogen-bonded motif is slightly less favourable. Moreover, the formation energy of the whole fragment weakens to 2111.9 kcal mol 21 .…”

“…10 Since then, although they are quite rare, 11,12 a number of coordination conglomerates have been reported. 13 Spontaneous resolution of six-coordinate complexes is clearly the most common, [14][15][16][17][18][19][20][21][22][23] but four-coordinate, [24][25][26] five-coordinate, 27 seven-coordinate, 28 eightcoordinate 29 and nine-coordinate 30 systems have also been described in the literature.…”