Enantioselective Cross‐Exchange between C−I and C−C σ Bonds

• Published in: Angewandte Chemie International Edition Vol. 58; no. 20; pp. 6747 - 6751
• Main Authors: Sun, Yu‐Li, Wang, Xing‐Ben, Sun, Feng‐Na, Chen, Qian‐Qian, Cao, Jian, Xu, Zheng, Xu, Li‐Wen
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 13.05.2019; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Aromatic compounds; asymmetric catalysis; Bromides; Catalysis; Chemistry; Chemistry, Multidisciplinary; Covalent bonds; C−C activation; Enantiomers; Exchanging; Iodides; Palladium; Physical Sciences; reaction mechanisms; Science & Technology; small-ring systems; ACTIVATION; CARBOIODINATION; REVERSIBLE OXIDATIVE ADDITION; reaction mechanisms; CATALYZED REACTION; asymmetric catalysis; CLEAVAGE; C-C activation; HALIDE REDUCTIVE ELIMINATION; ARYL HALIDES; small-ring systems; ATOM-TRANSFER; palladium; CARBON-CARBON; CYCLOBUTANONES; C−C activation
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201902029

A palladium‐catalyzed enantioselective intramolecular σ‐bond cross‐exchange between C−I and C−C bonds is realized, providing chiral indanones bearing an alkyl iodide group and an all‐carbon quaternary stereocenter. Pd/TADDOL‐derived phosphoramidite is found to be an efficient catalytic system for both C−C bond cleavage and alkyl iodide reductive elimination. In addition to aryl iodides, aryl bromides can also be used for this transformation in the presence of KI. Density‐functional theory (DFT) calculation studies support the ring‐opening of cyclobutanones occuring through an oxidative addition/reductive elimination process involving PdIV species. In exchange: An enantioselective cross‐exchange between C−I and C−C bonds is realized by palladium‐catalyzed sequential oxidative addition and reductive elimination. Chiral indanones bearing an alkyl iodide group and an all‐carbon quaternary stereocenter are synthesized in good yields and enantioselectivities.