Synthesis and Penicillin‐binding Protein Inhibitory Assessment of Dipeptidic 4‐Phenyl‐β‐lactams from α‐Amino Acid‐derived Imines
摘要:
AbstractMonocyclic β‐lactams revive the research field on antibiotics, which are threatened by the emergence of resistant bacteria. A six‐step synthetic route was developed, providing easy access to new 3‐amino‐1‐carboxymethyl‐4‐phenyl‐β‐lactams, of which the penicillin‐binding protein (PBP) inhibitory potency was demonstrated biochemically.
与文献报道相反,色氨酸甲酯的苄叉亚胺在二甲苯中的Pictet-Spengler环化发生得非常缓慢,即使有的话,在没有酸的情况下也是如此。环化反应是布朗斯台德酸催化的,环化速率与布朗斯台德酸的p K a及其浓度有关。所有研究的酸催化剂都给出了基本相同的四氢-β-咔啉的立体异构体混合物(顺式:反式,约1.2:1)。色胺的苄叉亚胺在相同条件下可平滑环化。
The l -tert-leucine-derived AmidPhos/silver(I) catalytic system has been developed for the asymmetric [3+2] cycloaddition of azomethineylides with electronic-deficient alkenes with or without Et3N. Under optimal conditions, highly functionalized endo-4-pyrrolidines were obtained with modest to high yields (up to 99% yield) and enantioselectivities (up to 98% ee).
From Bioactive Pyrrolidino[3,4-c]pyrrolidines to more Bioactive Pyrrolidino[3,4-b]pyrrolidines via Ring-Opening/Ring-Closing Promoted by Sodium Methoxide
作者:H. Dondas、José Sansano、Samet Belveren、Olatz Larrañaga、Samet Poyraz、Mahmut Ülger、Ertan Şahin、Marcos Ferrándiz-Saperas、M. de Gracia Retamosa、Abel de Cózar
DOI:10.1055/s-0037-1611356
日期:2019.4
as potential candidates for antibacterial and antimycobacterial activities. The process involving a rearrangement of pyrrolidino[3,4-c]pyrrolidine to another pyrrolidino[3,4-b]pyrrolidine using sodiummethoxide as base is fully studied. The effects of the substituents are analyzed during the ring-opening/ring-closing sequence. Computational studies are also performed to explain the importance of susbstituents
¥计算的通讯作者:abel.decozar@ehu.es 抽象的 充分研究了涉及使用甲醇钠作为碱将吡咯烷酮[3,4- c ]吡咯烷重排为另一种吡咯烷酮[3,4- b ]吡咯烷的过程。在开环/闭环过程中分析取代基的作用。还进行了计算研究,以解释取代基和季碳的重要性,特别是当起始原料中存在(3-吲哚基)甲基时。最后,所有样品均被评估为抗菌和抗分枝杆菌活性的潜在候选者。 充分研究了涉及使用甲醇钠作为碱将吡咯烷酮[3,4- c ]吡咯烷重排为另一种吡咯烷酮[3,4- b ]吡咯烷的过程。在开环/闭环过程中分析取代基的作用。还进行了计算研究,以解释取代基和季碳的重要性,特别是当起始原料中存在(3-吲哚基)甲基时。最后,所有样品均被评估为抗菌和抗分枝杆菌活性的潜在候选者。
Observations on the pictet-spengler synthesis of 1,2,3,4-tetrahydro-β-carbolines
The Pictet-Spengler cyclisation of the benzylideneimine of tryptophan methyl ester in xylene, contrary to literature reports, occurs extremely slowly, if at all, in the absence of acids. The cyclisation is Bronsted acid catalysed and the rate of cyclisation is related to the pKa of the Bronsted acid and its concentration. All the acid catalysts studied give essentially the same stereoisomeric mixture
与文献报道相反,色氨酸甲酯的苄叉亚胺在二甲苯中的Pictet-Spengler环化发生得非常缓慢,即使有的话,在没有酸的情况下也是如此。环化反应是布朗斯台德酸催化的,环化速率与布朗斯台德酸的p K a及其浓度有关。所有研究的酸催化剂都给出了基本相同的四氢-β-咔啉的立体异构体混合物(顺式:反式,约1.2:1)。色胺的苄叉亚胺在相同条件下可平滑环化。
1,3-Dipolar cycloaddition reactions of imines of α-amino-acid esters: X-ray crystal and molecular structure of methyl 4-(2-furyl)-2,7-diphenyl-6,8-dioxo-3,7-diazabicyclo[3.3.0]octane-2-carboxylate
Imines of α-amino acid esters undergo a wide range of cycloadditions probably via their 1,3-dipolar tautomers and the stereochemistry of one adduct has been determined by X-ray crystallography.