we describe the synthesis of potent and selective quinolone-based histone deacetylase 6 (HDAC6) inhibitors. The quinolone moiety has been exploited as an innovative bioactive cap-group for HDAC6 inhibition; its synthesis was achieved by applying a multicomponent reaction. The optimization of potency and selectivity of these products was performed by employing computational studies which led to the
Spin-Center Shift-Enabled Direct Enantioselective α-Benzylation of Aldehydes with Alcohols
作者:Eric D. Nacsa、David W. C. MacMillan
DOI:10.1021/jacs.7b12768
日期:2018.3.7
two-electron pathways. We report herein an enantioselective α-benzylation of aldehydes using alcohols as alkylating agents based on the mechanistic principle of spin-center shift. This strategy harnesses the dual activation modes of photoredox and organocatalysis, engaging the alcohol by SCS and capturing the resulting benzylic radical with a catalytically generated enamine. Mechanistic studies provide
大自然通常使用醇作为离去基团,因为 DNA 生物合成依赖于通过自由基介导的“自旋中心转移”(SCS)机制从核糖核苷二磷酸中去除水。然而,由于醇在双电子途径中的低反应性,醇在合成化学中作为烷化剂仍然没有得到充分利用。我们在此报告了基于自旋中心位移的机械原理,使用醇作为烷化剂的醛的对映选择性 α-苄基化。该策略利用光氧化还原和有机催化的双重激活模式,通过 SCS 与醇结合,并用催化生成的烯胺捕获产生的苄基自由基。机理研究为 SCS 作为关键的基本步骤提供了证据,确定了竞争反应的起源,
Cα-substituted 4-methylpyridines have been N-lithiated and reacted with chlorotrimethylsilane and other electrophiles. The lithiated Cα-NMe2 substituted intermediate shows an interesting dichotomy of behavior towards electrophiles: It represents the borderline between compounds for which an extreme N or Cα regio-nucleophilicity is observed.
asymmetric alkylation of aldehydes was studied, by using a homemade, custom-designed photoreactor for reactions under cryogenic conditions. Going from microfluidic conditions up to a 10 mL mesofluidic reactor, an increase of productivity by almost 18000 % compared to the batch reaction was demonstrated. Finally, for the first time, a stereoselective photoredox organocatalytic continuous flow reaction
通过使用自制、定制设计的光反应器在低温条件下进行反应,研究了醛的连续流动、对映选择性、有机光氧化还原催化不对称烷基化。从微流控条件到 10 mL 中流控反应器,与分批反应相比,生产率提高了近 18000%。最后,首次成功实现了在完全伸缩过程中用于活性药物成分 (API) 合成的立体选择性光氧化还原有机催化连续流动反应。最终工艺由四个操作单元组成:连续流动下可见光驱动的不对称催化苄基化、在线连续后处理、中和和最终的氧化酰胺化步骤,得到 95% ee 的药物活性分子
Semiconductor quantum dots photosensitizing release of anticancer drug
A new photo-controlled anticancer drug release system is reported based on the photo-induced electron transfer (PET) between semiconductor quantum dots (QDs) and N-methyl-4-picolinium (NAP) ester 1 under the excitation of visible light.