Total synthesis of micrococcin P1 and thiocillin I enabled by Mo(<scp>vi</scp>) catalyst
作者:Siddhartha Akasapu、Aaron B. Hinds、Wyatt C. Powell、Maciej A. Walczak
DOI:10.1039/c8sc04885a
日期:——
Thiopeptides are a class of potent antibiotics with promising therapeutic potential. We developed a novel Mo(VI)-oxide/picolinic acid catalyst for the cyclodehydration of cysteine peptides to form thiazoline heterocycles. With this powerful tool in hand, we completed the total syntheses of two representative thiopeptide antibiotics: micrococcin P1 and thiocillin I. These two concise syntheses (15 steps
硫肽是一类具有良好治疗潜力的强效抗生素。我们开发了一种新型 Mo( VI )-氧化物/吡啶甲酸催化剂,用于半胱氨酸肽环脱水形成噻唑啉杂环。借助这个强大的工具,我们完成了两种具有代表性的硫肽抗生素的全合成:微球菌素 P1 和硫西林 I。这两种简洁的合成(15 个步骤,最长的线性序列)采用 C-H 激活策略来安装三取代的吡啶核心和噻唑基团。通过针对一系列革兰氏阳性细菌的测量,该合成材料显示出有前景的抗菌特性。
MACROCYCLIC INHIBITORS OF FLAVIVIRIDAE VIRUSES
申请人:Selcia Ltd.
公开号:US20140030221A1
公开(公告)日:2014-01-30
Provided are compounds of Formula I:
and pharmaceutically acceptable salts and esters thereof. The compounds, compositions, and methods provided are useful for the treatment of virus infections, particularly hepatitis C infections.
Provided are compounds of Formula I:
and pharmaceutically acceptable salts and esters thereof. The compounds, compositions, and methods provided are useful for the treatment of virus infections, particularly hepatitis C infections.
pseudoprolines. To minimize the loss of the Fmoc protection, we optimized the saponification conditions and included a calcium additive that protected the other base-sensitive functionalities and improved the yield of the free acid (36–82%). The reaction requires a combination of CaCl2 and NaOH in a mixture of iPrOH and water at room temperature.
Highly Enantioselective Regiodivergent Allylic Alkylations of MBH Carbonates with Phthalides
作者:Fangrui Zhong、Jie Luo、Guo-Ying Chen、Xiaowei Dou、Yixin Lu
DOI:10.1021/ja303115m
日期:2012.6.20
Phthalides were used for the first time in the allylic alkylation reactions with MBH carbonates for the creation of chiral 3,3-disubstituted phthalides. Highly enantioselective regiodivergent synthesis of gamma-selective or beta-selective allylic alkylation products was achieved by employing bifunctional chiral phosphines or multifunctional tertiary amine-thioureas as the catalyst, respectively. It was demonstrated that proper selection of catalysts and reaction conditions would differentiate an S(N)2'-S(N)2' pathway and an addition-elimination process, yielding different regioisomers of the allylic alkylation products in a highly enantiomerically pure form.