Enantioselective Copper-Catalyzed Intramolecular O−H Insertion: An Efficient Approach to Chiral 2-Carboxy Cyclic Ethers
摘要:
A copper-catalyzed asymmetric intramolecular O-H insertion of omega-hydroxy-alpha-diazoesters has been accomplished by using chiral spiro bisoxazoline ligands. This highly enantioselective intramolecular O-H insertion reaction provides an efficient approach to a variety of synthetically important chiral 2-carboxy cyclic ethers with different ring sizes as well as substitution patterns.
Synthesis of planar chiral [2.2]paracyclophane-based bisoxazoline ligands bearing no central chirality and application to Cu-catalyzed asymmetric O–H insertion reaction
作者:Shinji Kitagaki、Kenta Sugisaka、Chisato Mukai
DOI:10.1039/c5ob00452g
日期:——
C2-symmetric planar chiral [2.2]paracyclophane-based bisoxazoline ligands effectively control the asymmetric induction during the Cu-catalyzed O–H insertion reaction of α-diazo esters.
A copper-catalyzed asymmetric intramolecular O-H insertion of omega-hydroxy-alpha-diazoesters has been accomplished by using chiral spiro bisoxazoline ligands. This highly enantioselective intramolecular O-H insertion reaction provides an efficient approach to a variety of synthetically important chiral 2-carboxy cyclic ethers with different ring sizes as well as substitution patterns.
Iron‐Catalyzed Aminomethyloxygenative Cyclization of Hydroxy‐α‐diazoesters with
<i>N,O</i>
‐Aminals
A new and efficient cyclization reaction has been developed to synthesize cyclic α,α‐disubstituted β‐amino esters via iron‐catalyzed intramolecular aminomethyloxygenative cyclization of diazo compounds with N,O‐aminal under mild reaction conditions. A broad range of hydroxy‐α‐diazoesters with different substituents and various N,O‐aminals were compatible with this protocol, affording the corresponding