Enantioselective Direct Amination of α-Cyanoacetates Catalyzed by Bifunctional Chiral Ru and Ir Amido Complexes
作者:Yasuharu Hasegawa、Masahito Watanabe、Ilya D. Gridnev、Takao Ikariya
DOI:10.1021/ja710273s
日期:2008.2.1
The bifunctional chiral amido Ir complex catalyzed asymmetric electrophilic direct amination of alpha-substituted alpha-cyanoacetates using azodicarboxylates proceeds rapidly to provide the corresponding hydrazine adducts in high yields and with excellent ea values.
Asymmetric Construction of Quaternary Stereocenters by Direct Organocatalytic Amination of α-Substituted α-Cyanoacetates and β-Dicarbonyl Compounds
作者:Steen Saaby、Marco Bella、Karl Anker Jørgensen
DOI:10.1021/ja047704j
日期:2004.7.1
The first organocatalytic highly enantioselective reactions of substituted alpha-cyanoacetates and beta-dicarbonyl compounds with azodicarboxylates are reported. In the presence of 0.1-5 mol % of a quinidine-derived alkaloid beta-ICD, optically active quaternary hydrazine adducts are obtained in very high yields and with enantioselectivities up to >98% ee. A two-step procedure for the cleavage of the hydrazine N-N bond using SmI2 is also demonstrated.
Asymmetric Assembly of All-Carbon Tertiary/Quaternary Nonadjacent Stereocenters through Organocatalytic Conjugate Addition of α-Cyanoacetates to a Methacrylate Equivalent
作者:Igor Iriarte、Silvia Vera、Eider Badiola、Antonia Mielgo、Mikel Oiarbide、Jesús M. García、José M. Odriozola、Claudio Palomo
DOI:10.1002/chem.201603082
日期:2016.9.12
An efficient, highly diastereo‐ and enantioselective assembly of acyclic carbonyl fragments possessing nonadjacent all‐carbon tertiary/quaternary stereoarrays is reported based on a Brønsted base catalyzed Michael addition/α‐protonation sequence involving α‐cyanoacetates and 2,4‐dimethyl‐4‐hydroxypenten‐3‐one as novel methacrylate equivalent.