Iridium-Catalyzed Enantioselective Fluorination of Racemic, Secondary Allylic Trichloroacetimidates
摘要:
The Ir-catalyzed enantioselective fluorination of racemic, branched allylic trichloroacetiinidates with Et3N center dot 3HF is a mild and efficient route for selective incorporation of fluoride ion into allylic systems. We herein describe the asymmetric fluorination of racemic, secondary allylic electrophiles with Et3N center dot 3HF using a chiral-diene-ligated Ir complex. The methodology enables the formation of acyclic fluorine-containing compounds in good yields with excellent levels of asymmetric induction and overcomes the limitations previously associated with the eiiantioselective construction of secondary allylic fluorides bearing alpha-linear substituents.
Fully selective intramolecular ortho photocycloaddition of 4-(4-methoxy-phenoxy)-3-(N3-benzoylthymin-1-yl)but-1- ene: an unprecedented benzene–thymine photocycloaddition
作者:Wim Saeyens、Roger Busson、Johan Van der Eycken、Piet Herdewijn、Denis De Keukeleire
DOI:10.1039/a700554g
日期:——
On irradiation of
4-(4-methoxyphenoxy)-3-(N
3
-benzoylthymin-1-yl)but-1-e
ne 1 at 254 nm in THF a single photoadduct 2 is formed as a result of
chemo-, regio- and stereo-selective intramolecular ortho
photocycloaddition of the thymine double bond to the 1,2-positions of the
phenyl ring.
Highly Regio‐ and Enantioselective Cu/Pd Co‐Catalyzed Allylic Alkylation of α‐pyridyl‐α‐fluoroesters: Construction of Quaternary C−F Stereocenters
作者:Xinlong Yan、Zongwei Li、Lin Fan、Jiashan Li、Guodu Liu
DOI:10.1002/asia.202300160
日期:2023.6
efficient synergistic Pd/Cu catalyst system for the highly regioselective asymmetric allylation of α-pyridyl-α-fluoroesters constructed straight-chain allyl products containing C−F quaternarystereocenter. A series of aryl- and aliphatic-substituted straight-chain allyl products were obtained in high yields, excellent enantioselectivities and E/Z-selectivities (up to 98% yield, 98 : 2 er, and >20 : 1