13734-36-6Relevant articles and documents
Diastereoselective synthesis of the 5-hydroxy-pyrrolidinone amino acid of the microsclerodermins and model studies for an end-game strategy for microsclerodermin B
Winter, Christian,Pullin, Robert D.C.,Donohoe, Timothy J.
, p. 602 - 605 (2017)
The first diastereoselective synthesis of the 5-hydroxy-pyrrolidinone amino acid common to eight members of the microsclerodermin family is presented. Our strategy involves formal hydration of an unsaturated precursor via the use of a two-step hydroxybromination-debromination protocol; this procedure provides exclusively the requisite 4,5-cis-pyrrolidinone. Furthermore model studies are presented that indicated the potential viability of this hydration strategy in the context of a synthesis of microsclerodermin B.
CD-sensitive Zn-porphyrin tweezer host-guest complexes, part 2: Cis- and trans-3-hydroxy-4-aryl/alkyl-β-lactams. A case study
Chen, Yihui,Petrovic, Ana G.,Roje, Marin,Pescitelli, Gennaro,Kayser, Margaret M.,Yang, Yan,Berova, Nina,Proni, Gloria
, p. 140 - 152 (2010)
This article describes an application of the host-guest chiral recognition approach called tweezer methodology for the determination of the absolute configuration of 3-hydroxy-β-lactams. These substrates represent challenging cases due to their chemical reactivity, the presence of multiple stereogenic centers and several functional groups which offer various possibilities of binding to the Zn-porphyrin host. OPLS-2005, the force field used in this work to predict the interporphyrin twist, modeled correctly the host-guest complexation mechanism and revealed conformational details of the bound substrates. The computational study also suggested that in cases where an increase in the magnitude of the stereodifferentiation and an intense experimental CD are observed, the bound conformation of the conjugates are hydrogen bonded. The present investigation provides evidence that when the tweezer method is assisted by the OPLS-2005 based computational approach, it can be successfully applied to the con-figurational and conformational elucidation of multi-functional compounds with multiple stereogenic centers.
Cyclic Poly(α-peptoid)s by Lithium bis(trimethylsilyl)amide (LiHMDS)-Mediated Ring-Expansion Polymerization: Simple Access to Bioactive Backbones
Salas-Ambrosio, Pedro,Tronnet, Antoine,Since, Marc,Bourgeade-Delmas, Sandra,Stigliani, Jean-Luc,Vax, Amelie,Lecommandoux, Sébastien,Dupuy, Bruno,Verhaeghe, Pierre,Bonduelle, Colin
, p. 3697 - 3702 (2021)
Cyclic polymers display unique physicochemical and biological properties. However, their development is often limited by their challenging preparation. In this work, we present a simple route to cyclic poly(α-peptoids) from N-alkylated-N-carboxyanhydrides (NNCA) using LiHMDS promoted ring-expansion polymerization (REP) in DMF. This new method allows the unprecedented use of lysine-like monomers in REP to design bioactive macrocycles bearing pharmaceutical potential against Clostridioides difficile, a bacterium responsible for nosocomial infections.
Alkali-metal hexamethyldisilazide initiated polymerization on alpha-amino acid N-substituted N-carboxyanhydrides for facile polypeptoid synthesis
Wu, Yueming,Zhou, Min,Chen, Kang,Chen, Sheng,Xiao, Ximian,Ji, Zhemin,Zou, Jingcheng,Liu, Runhui
, p. 1675 - 1678 (2021)
Polypeptoids have been explored as mimics of polypeptides, owing to polypeptoids’ superior stability upon proteolysis. Polypeptoids can be synthesized from one-pot ring-opening polymerization of amino acid N-substituted N-carboxyanhydrides (NNCAs). However, the speed of polymerization of NNCAs can be very slow, especially for NNCAs bearing a bulky N-substitution group. This hindered the exploration on polypeptoids with more diverse structures and functions. Therefore, it is in great need to develop advanced strategies that can accelerate the polymerization on inactive NNCAs. Hereby, we report that lithium/sodium/potassium hexamethyldisilazide (Li/Na/KHMDS) initiates a substantially faster polymerization on NNCAs than do commonly used amine initiators, especially for NNCAs with bulky N-substitution group. This fast NNCA polymerization will increase the structure diversity and application of polypeptoids as synthetic mimics of polypeptides.
Cyclic poly(α-peptoid)s and their block copolymers from N-heterocyclic carbene-mediated ring-opening polymerizations of N-substituted N-carboxylanhydrides
Li, Guo,Donghui, Zhang
, p. 18072 - 18074 (2009)
(Chemical Equation Presented) N-Heterocyclic carbene (NHC)-mediated ring-opening polymerization (ROP) of N-substituted N-carboxylanhydride ( NR-NCA) yields cyclic poly(4-peptoid)s with controlled molecular weights (Mn = 3-30 kg mol-1) and narrow molecular weight distributions (PDI = 1.04-1.12). The reactions exhibit characteristics of a living polymerization with minimal chain transfer. This enables the facile synthesis of cyclic diblock copoly(4-peptoid)s through sequential monomer addition. The cyclic polymer architectures were verified by MALDI-TOF mass spectrometry and intrinsic viscosity measurements. Mark-Houwink-Sakurada plot analyses revealed that cyclic poly(4-peptoid)s prepared from NHC-mediated polymerizations exhibit lower intrinsic viscosities than their linear analogues prepared from primary amine-initiated polymerizations. The ratio of their intrinsic viscosities is consistent with the former being mostly cyclic.
Photoenzymatic Synthesis of α-Tertiary Amines by Engineered Flavin-Dependent "ene"-Reductases
Gao, Xin,Turek-Herman, Joshua R.,Choi, Young Joo,Cohen, Ryan D.,Hyster, Todd K.
supporting information, p. 19643 - 19647 (2021/12/01)
α-Tertiary amines are a common motif in pharmaceutically important molecules but are challenging to prepare using asymmetric catalysis. Here, we demonstrate engineered flavin-dependent ‘ene'-reductases (EREDs) can catalyze radical additions into oximes to prepare this motif. Two different EREDs were evolved into competent catalysts for this transformation with high levels of stereoselectivity. Mechanistic studies indicate that the oxime contributes to the enzyme templated charge-transfer complex formed between the substrate and cofactor. These products can be further derivatized to prepare a variety of motifs, highlighting the versatility of ERED photoenzymatic catalysis for organic synthesis.
INHIBITORS OF BRUTON'S TYROSINE KINASE AND METHODS OF THEIR USE
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Page/Page column 155, (2018/06/30)
Compounds of formula (I') and methods of their use and preparation, as well as compositions comprising compounds of formula (I').