Iron‐Catalyzed Tertiary Alkylation of Terminal Alkynes with 1,3‐Diesters via a Functionalized Alkyl Radical
作者:Ming‐Qing Tian、Zhen‐Yao Shen、Xuefei Zhao、Patrick J. Walsh、Xu‐Hong Hu
DOI:10.1002/anie.202100641
日期:2021.4.19
Direct oxidative C(sp)−H/C(sp3)−H cross‐coupling offers an ideal and environmentally benign protocol for C(sp)−C(sp3) bond formations. As such, reactivity and site‐selectivity with respect to C(sp3)−H bond cleavage have remained a persistent challenge. Herein is reported a simple method for iron‐catalyzed/silver‐mediated tertiary alkylation of terminal alkynes with readily available and versatile 1
Cooperative Melting in Caged Dimers of Rigid Small Molecule-DNA Hybrids
作者:Brian R. Stepp、Julianne M. Gibbs-Davis、Dorothea L. F. Koh、SonBinh T. Nguyen
DOI:10.1021/ja801572n
日期:2008.7.1
Rigid small-molecule DNA hybrids (rSMDHs) have been synthesized with three DNA strands attached to a rigid tris(phenylacetylene) core. When combined under dilute conditions, complementary rSMDHs form cagedimers that melt at >10 degrees C higher and much sharper than either unmodified DNA duplexes or rSMDH aggregates formed at higher concentrations. With a 2.97 average number of cooperative duplexes
已经合成了刚性小分子 DNA 杂交体 (rSMDH),其中三个 DNA 链连接到刚性三(苯乙炔)核心。当在稀释条件下结合时,互补的 rSMDH 形成笼二聚体,其熔化温度高于 10 摄氏度,比未修饰的 DNA 双链体或在更高浓度下形成的 rSMDH 聚合体更锐利。这些笼状二聚体的平均合作双链数为 2.97,构成了明确定义的 DNA 小分子结构中合作熔解的第一个例子,证明了局部几何形状和离子浓度在基于 DNA 的杂交/去杂交中的重要作用。材料。
Regio- and Chemoselective Deprotection of Primary Acetates by Zirconium Hydrides
作者:Marine Gavel、Thibaut Courant、Antoine Yvan Philippe Joosten、Thomas Lecourt
DOI:10.1021/acs.orglett.8b03947
日期:2019.4.5
A combination of DIBAL-H and Cp2ZrCl2 is shown to promote the regioselective cleavage of primary acetates on a broad scope of substrates, ranging from carbohydrates to terpene derivatives, with a high tolerance toward protecting groups and numerous functionalities found in natural products and bioactive compounds. Apart from providing highly valuable building blocks in only two steps from biosourced raw materials, this selective de-O-acetylation should also be strongly helpful to solve selectivity issues in organic synthesis.