93643-64-2Relevant articles and documents
Application of Allylzinc Reagents as Nucleophiles in Matteson Homologations
Andler, Oliver,Kazmaier, Uli
, p. 8439 - 8444 (2021/10/25)
Allylzinc reagents are versatile nucleophiles that can be used in Matteson homologations. The linear substitution products are formed almost exclusively, and excellent E selectivities are observed in reactions of reagents with sterically demanding or aryl
Emergence of a catalytic tetrad during evolution of a highly active artificial aldolase
Obexer, Richard,Godina, Alexei,Garrabou, Xavier,Mittl, Peer R. E.,Baker, David,Griffiths, Andrew D.,Hilvert, Donald
, p. 50 - 56 (2017/03/21)
Designing catalysts that achieve the rates and selectivities of natural enzymes is a long-standing goal in protein chemistry. Here, we show that an ultrahigh-throughput droplet-based microfluidic screening platform can be used to improve a previously optimized artificial aldolase by an additional factor of 30 to give a >10 9 rate enhancement that rivals the efficiency of class I aldolases. The resulting enzyme catalyses a reversible aldol reaction with high stereoselectivity and tolerates a broad range of substrates. Biochemical and structural studies show that catalysis depends on a Lys-Tyr-Asn-Tyr tetrad that emerged adjacent to a computationally designed hydrophobic pocket during directed evolution. This constellation of residues is poised to activate the substrate by Schiff base formation, promote mechanistically important proton transfers and stabilize multiple transition states along a complex reaction coordinate. The emergence of such a sophisticated catalytic centre shows that there is nothing magical about the catalytic activities or mechanisms of naturally occurring enzymes, or the evolutionary process that gave rise to them.
Improved conditions for the proline-catalyzed aldol reaction of acetone with aliphatic aldehydes
Martínez, Alberto,Zumbansen, Kristina,D?hring, Arno,Van Gemmeren, Manuel,List, Benjamin
supporting information, p. 932 - 934 (2014/05/06)
The proline-catalyzed asymmetric aldol reaction between aliphatic aldehydes and acetone has, to date, remained underdeveloped. Challenges in controlling this reaction include avoiding undesired side reactions such as aldol condensation and self-aldolization. In recent years we have developed optimized conditions, which enable high yields and good to excellent enantioselectivities, and which are presented in this communication. Georg Thieme Verlag Stuttgart New York.