A Triazole Organocatalyst with Spiropyrrolidine Framework and its Application to the Catalytic Asymmetric Addition of Nitromethane to α,β-Unsaturated Aldehydes
A series of new water-compatible “spiropyrrolidine triazole” catalysts was designed and synthesized. The asymmetric Michael addition of nitromethane and α,β-unsaturatedaldehydes in an aqueous system was investigated to evaluate these new catalysts, and the resulting adducts were obtained with excellent enantioselectivity (up to 95.5% ee) and moderate to good yield (63–88%).
Reactivity and Selectivity of Iminium Organocatalysis Improved by a Protein Host
作者:Alexander R. Nödling、Katarzyna Świderek、Raquel Castillo、Jonathan W. Hall、Antonio Angelastro、Louis C. Morrill、Yi Jin、Yu-Hsuan Tsai、Vicent Moliner、Louis Y. P. Luk
DOI:10.1002/anie.201806850
日期:2018.9.17
There has been growing interest in performing organocatalysis within a supramolecular system as a means of controlling reaction reactivity and stereoselectivity. Here, a protein is used as a host for iminium catalysis. A pyrrolidine moiety is covalently linked to biotin and introduced to the proteinhost streptavidin for organocatalytic activity. Whereas in traditional systems stereoselectivity is
Gene Fusion and Directed Evolution to Break Structural Symmetry and Boost Catalysis by an Oligomeric C−C Bond‐Forming Enzyme
作者:Guangcai Xu、Andreas Kunzendorf、Michele Crotti、Henriëtte J. Rozeboom、Andy‐Mark W. H. Thunnissen、Gerrit J. Poelarends
DOI:10.1002/anie.202113970
日期:2022.2.14
Less symmetry, more diversity: Here we show that gene duplication and fusion to break structural symmetry, allowing independent sequence diversification of neighboring subunits by directed evolution, is a powerful strategy to boost catalysis by a promiscuous homohexameric 4-oxalocrotonate tautomerase (4-OT), enabling efficient asymmetric Michael additions.