共查询到20条相似文献,搜索用时 15 毫秒
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Sri Krishna Nimmagadda Mingyu Liu Malkanthi K. Karunananda De‐Wei Gao Omar Apolinar Jason S. Chen Peng Liu Keary M. Engle 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(12):3963-3967
A palladium(II)‐catalyzed enantioselective α‐alkylation of azlactones with nonconjugated alkenes is described. The reaction employs a chiral BINOL‐derived phosphoric acid as the source of stereoinduction, and a cleavable bidentate directing group appended to the alkene to control the regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of azlactones were found to be compatible under the optimal reaction conditions to afford products bearing α,α‐disubstituted α‐amino‐acid derivatives with high yields and high enantioselectivity. 相似文献
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José Enrique Gómez Dr. Wusheng Guo Silvia Gaspa Prof. Dr. Arjan W. Kleij 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(47):15231-15234
The first general asymmetric synthesis of γ,γ‐disubstituted γ‐amino acids by copper‐catalyzed ring opening of nonstrained lactones with amines is reported. This approach features ample scope, operational simplicity, and wide functional‐group diversity. The catalytic process allows access to a series of highly functionalized enantioenriched γ‐amino acids featuring quaternary stereocenters with excellent enantiomeric ratios of up to 98:2 and excellent yields of up to 98 %. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(6):1528-1531
Herein we report acid‐directed β‐C(sp3)‐H arylation of α‐amino acids enabled by pyridine‐type ligands. This reaction does not require the installation of an exogenous directing group, is scalable, and enables the preparation of Fmoc‐protected unnatural amino acids in three steps. The pyridine‐type ligands are crucial for the development of this new C(sp3)‐H arylation. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(39):11959-11963
The first asymmetric synthesis of important α,α‐disubstituted N‐alkyl allyl amine scaffolds through allylic substitution is reported. This approach is based on palladium catalysis and features ample scope with respect to both the allylic precursor and amine reagent, and high asymmetric induction with enantiomeric ratios (e.r.) up to 98.5:1.5. The use of less‐reactive anilines is also feasible, providing enantioenriched α,α‐disubstituted N‐aryl allylic amines. 相似文献
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