stereodivergent Pd/Cu catalyst system has been developed for the unprecedented dynamickineticasymmetrictransformation (DyKAT) of racemic unsymmetrical 1,3-disubstituted allylic acetates with prochiral aldimine esters. A series of α,α-disubstituted α-amino acids bearing vicinal stereocenters were easily prepared with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to >20:1 dr). By
One Stone Two Birds—Enantioselective Bimetallic Catalysis for<scp>α‐Amino</scp>Acid Derivatives with an Allene Unit
作者:Junzhe Xiao、Haibo Xu、Xiaohong Huo、Wanbin Zhang、Shengming Ma
DOI:10.1002/cjoc.202100002
日期:2021.7
3-butadienyl α-amino acid derivatives in high to excellent yields with excellent enantioselectivities has been developed. The synthetic versatility of this reaction has been demonstrated by gram-scale synthesis, a catalytic enantioselective synthesis of naturally occurring (S)-2-amino-4,5-hexadienoic acid A, and conversions to several useful chemicals, such as optically active α-amino acids, β-amino alcohols
通过协同双金属 Pd/Cu 催化对无环和环状 α-亚氨基羧酸盐进行高度对映选择性 2,3-烯丙基化,使用相同的市售 ( R , R p ) -i Pr-FOXAP(也称为 Phosferrox, ( R , R ) -[2-(4'- i-丙基恶唑啉-2'-基)二茂铁基]二苯基膦)配体用于提供光学活性的 2,3-丁二烯基 α-氨基酸衍生物,收率高至极好,具有极好的对映选择性. 该反应的合成多功能性已通过克级合成证明,这是一种天然存在的催化对映选择性合成(S)-2-氨基-4,5-己二烯酸 A,并转化为几种有用的化学物质,例如光学活性的 α-氨基酸、β-氨基醇、带有丙二烯部分的潜在手性恶唑啉配体和双环酮化合物。基于关键钯预催化剂的分离和控制实验,已经广泛研究了涉及两种金属和单个手性配体的作用的机制。
Stereoselective and Site-Specific Allylic Alkylation of Amino Acids and Small Peptides via a Pd/Cu Dual Catalysis
alkylation of Schiff base activated amino acids and small peptides via a Pd/Cu dual catalysis. A range of noncoded α,α-dialkyl α-aminoacids were easily synthesized in high yields and with excellent enantioselectivities (up to >99% ee). Furthermore, a direct and highly stereoselective synthesis of small peptides with enantiopure α-alkyl or α,α-dialkyl α-aminoacids residues incorporated at specific sites
A Facile Cu(I)/BINAP-Catalyzed Asymmetric Approach to Functionalized Pyroglutamate Derivatives Bearing a Unique Quaternary Stereogenic Center
作者:Huai-Long Teng、Fei-Long Luo、Hai-Yan Tao、Chun-Jiang Wang
DOI:10.1021/ol202326j
日期:2011.10.21
pyroglutamate derivatives bearing a unique quaternary stereogenic center has been developed via Cu(I)/BINAP-catalyzed tandem Michael addition–elimination of α-substituted aldimino esters with Morita–Baylis–Hillman (MBH) carbonates followed by a deprotection/lactamization protocol, which performs well over a broad scope of substrates and provides biologically active pyroglutamate derivatives in good yields