7766-48-5Relevant articles and documents
Total synthesis of guanacastepene A: A route to enantiomeric control
Mandal, Mihirbaran,Yun, Heedong,Dudley, Gregory B.,Lin, Songnian,Tan, Derek S.,Danishefsky, Samuel J.
, p. 10619 - 10637 (2005)
The goal of the total synthesis of guanacastepene A served as a focus to bring together several chemical inquiries. One involved the synthesis of fused 5,7-hydrazulenones (see structure 20). Another issue had to do with the mechanistic intermediates in re
Asymmetric Reductive Carbocyclization Using Engineered Ene Reductases
Heckenbichler, Kathrin,Schweiger, Anna,Brandner, Lea Alexandra,Binter, Alexandra,Toplak, Marina,Macheroux, Peter,Gruber, Karl,Breinbauer, Rolf
supporting information, p. 7240 - 7244 (2018/06/15)
Ene reductases from the Old Yellow Enzyme (OYE) family reduce the C=C double bond in α,β-unsaturated compounds bearing an electron-withdrawing group, for example, a carbonyl group. This asymmetric reduction has been exploited for biocatalysis. Going beyond its canonical function, we show that members of this enzyme family can also catalyze the formation of C?C bonds. α,β-Unsaturated aldehydes and ketones containing an additional electrophilic group undergo reductive cyclization. Mechanistically, the two-electron-reduced enzyme cofactor FMN delivers a hydride to generate an enolate intermediate, which reacts with the internal electrophile. Single-site replacement of a crucial Tyr residue with a non-protic Phe or Trp favored the cyclization over the natural reduction reaction. The new transformation enabled the enantioselective synthesis of chiral cyclopropanes in up to >99 % ee.
Improved synthesis of unnatural amino acids for peptide stapling
Li, Bo,Zhang, Jie,Xu, Yongjuan,Yang, Xiaoxiao,Li, Li
supporting information, p. 2374 - 2377 (2017/05/29)
The procedures for the synthesis of various α-alkenyl and alkyne amino acids were systematically optimized in light of enhancing atom economy, reducing hazardous reagent usage, and simplifying workup. By starting with Boc-Pro-OH and coupling with EDCI/DMAP followed by alkylation, chiral auxiliary was synthesized with high yield and enantioselectivity. For alkylation of the chiral complex, tBuONa was found and proved by quantitative calculation to be superior to tBuOK in generating more nucleophilic enolate salt, thereby can significantly enhance yield under room temperature. Final Fmoc protection was also dramatically facilitated in one-pot sequential manner by adding EDTA-2Na as the nickel chelator. Synthesis of α-bisalkenyl amino acid was also accomplished by achiral complex approach with high yield and efficacy. Accordingly, five most commonly used N-Fmoc protected α-alkenyl and alkynyl amino acids were synthesized and characterized.
Stabilized alpha helical peptides and uses thereof
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Sheet 2, (2016/05/19)
Novel polypeptides and methods of making and using the same are described herein. The polypeptides include cross-linking (“hydrocarbon stapling”) moieties to provide a tether between two amino acid moieties, which constrains the secondary structure of the polypeptide. The polypeptides described herein can be used to treat diseases characterized by excessive or inadequate cellular death.
