title: Asymmetric Latent Carbocation Catalysis with Chiral Trityl Phosphate.
abstract: Stable carbocations such as tritylium ions have been widely explored as organic Lewis acid catalysts and reagents in organic synthesis. However, achieving asymmetric carbocation catalysis remains elusive ever since they were first identified over one century ago. The challenges mainly come from their limited compatibility, scarcity of chiral carbocations, as well as the extremely low barrier to racemization of chiral carbenium ions. We reported here a latent concept for asymmetric carbocation catalysis. In this strategy, chiral trityl phosphate is employed as the carbocation precursor, which undergoes facile ionic dissociation upon mild external stimulation (e.g., acid, H-bonding, polar substrates) to form a catalytically active chiral ion pair for substrate activation and chiral induction. The latent strategy provides a solution for the long sought-after asymmetric carbocation catalysis as illustrated in three different enantioselective transformations.
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.|Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300071, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lv
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Qichao
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Xingren
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.|Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 300071, China.
authors.forename: Sanzhong
authors.initials: S
authors.lastname: Luo