Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany.
Molecules. 2021 Mar 24;26(7):1822. doi: 10.3390/molecules26071822.
A new class of bis-cyclometalated iridium(III) catalysts containing two inert cyclometalated 6--butyl-2-phenyl-2-indazole bidentate ligands or two inert cyclometalated 5--butyl-1-methyl-2-phenylbenzimidazoles is introduced. The coordination sphere is complemented by two labile acetonitriles, and a hexafluorophosphate ion serves as a counterion for the monocationic complexes. Single enantiomers of the chiral-at-iridium complexes (>99% er) are obtained through a chiral-auxiliary-mediated approach using a monofluorinated salicyloxazoline and are investigated as catalysts in the enantioselective conjugate addition of indole to an α,β-unsaturated 2-acyl imidazole and an asymmetric Nazarov cyclization.
介绍了一类新型双环金属铱(III)催化剂，它含有两个惰性的环金属化 6--丁基-2-苯基-2-苯并咪唑双齿配体或两个惰性的环金属化 5--丁基-1-甲基-2-苯基苯并咪唑。配位球由两个不稳定的乙腈分子补充，六氟磷酸根离子作为单阳离子配合物的抗衡离子。通过使用单氟化水杨醛恶唑啉的手性辅助介导方法，可以获得手性铱配合物的单一对映异构体（>99%ee），并将其作为催化剂用于吲哚与α，β-不饱和 2-酰基咪唑的对映选择性共轭加成反应和不对称 Nazarov 环化反应中。
