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Enantioselective Excited-State Photoreactions Controlled by a Chiral Hydrogen-Bonding Iridium Sensitizer.

ABSTRACT: Stereochemical control of electronically excited states is a long-standing challenge in photochemical synthesis, and few catalytic systems that produce high enantioselectivities in triplet-state photoreactions are known. We report herein an exceptionally effective chiral photocatalyst that recruits prochiral quinolones using a series of hydrogen-bonding and ?-? interactions. The organization of these substrates within the chiral environment of the transition-metal photosensitizer leads to efficient Dexter energy transfer and effective stereoinduction. The relative insensitivity of these organometallic chromophores toward ligand modification enables the optimization of this catalyst structure for high enantiomeric excess at catalyst loadings as much as 100-fold lower than the optimal conditions reported for analogous chiral organic photosensitizers.

SUBMITTER: Skubi KL

PROVIDER: S-EPMC5749223 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Enantioselective Excited-State Photoreactions Controlled by a Chiral Hydrogen-Bonding Iridium Sensitizer.

Skubi Kazimer L KL Kidd Jesse B JB Jung Hoimin H Guzei Ilia A IA Baik Mu-Hyun MH Yoon Tehshik P TP

Journal of the American Chemical Society 20171116 47

Stereochemical control of electronically excited states is a long-standing challenge in photochemical synthesis, and few catalytic systems that produce high enantioselectivities in triplet-state photoreactions are known. We report herein an exceptionally effective chiral photocatalyst that recruits prochiral quinolones using a series of hydrogen-bonding and π-π interactions. The organization of these substrates within the chiral environment of the transition-metal photosensitizer leads to effici ...[more]

PMID: 29087702

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