A new catalytic process for allyl ester cleavage has been developed by using a robust cationic CpRu(IV) π-allyl complex of 2-quinolinecarboxylic acid that can be stored for over six months in air without any loss of catalytic activity. The deprotection of various alcohols and acids can be attained simply with high reactivity and chemoselectivity under mild conditions. Furthermore, with continuous removal
Ti/Pd Bimetallic Systems for the Efficient Allylation of Carbonyl Compounds and Homocoupling Reactions
作者:Alba Millán、Araceli G. Campaña、Btissam Bazdi、Delia Miguel、Luis Álvarez de Cienfuegos、Antonio M. Echavarren、Juan M. Cuerva
DOI:10.1002/chem.201003315
日期:2011.3.28
The allylation, crotylation and prenylation of aldehydes and ketones with stable and easily handled allylic carbonates is promoted by a Ti/Pd catalytic system. This Ti/Pd bimetallic system is especially convenient for the allylation of ketones, which are infrequent substrates in other related protocols, and can be carried out intramolecularly to yield five‐ and six‐membered cyclic products with good
Ti / Pd催化体系可促进醛和酮与稳定且易于处理的烯丙基碳酸酯的烯丙基化,丁酰化和烯丙基化。这种Ti / Pd双金属体系特别适合于酮的烯丙基化,酮是其他相关规程中不常见的底物,并且可以在分子内进行生产,从而产生具有良好立体选择性的五元和六元环状产物。此外,Ti / Pd介导的还原反应和Würtz型二聚反应可以很容易地从碳酸烯丙酯和羧酸酯中进行。
Chemo-, regio-, and stereoselective Heck–Matsuda arylation of allylic alcohols under mild conditions
作者:Tohasib Yusub Chaudhari、Asik Hossian、Manash Kumar Manna、Ranjan Jana
DOI:10.1039/c5ob00235d
日期:——
Heck arylation with allylic alcohol is extremely challenging due to chemo-, regio-, and stereoselective scrambling. Here we report a mild protocol for the alcohol selective β- and α-arylation of allylic and cinnamyl alcohols respectively with aryldiazonium salts. The steric and electronic parameters of the alkene play a prominent role in the regioselectivity.
Dynamic pH responsivity of triazole-based self-immolative linkers
作者:Derrick A. Roberts、Ben S. Pilgrim、Tristan N. Dell、Molly M. Stevens
DOI:10.1039/d0sc00532k
日期:——
Triazole-based self-immolative linkers can be reversibly paused and restarted throughout their elimination cascades in response to environmental pH changes.
三唑基自解离连接物可以在环境pH变化的响应中通过其消除级联过程被可逆地暂停和重新启动。
Expanding the Scope and Orthogonality of PNA Synthesis
nucleic acids (PNAs) hybridize to natural oligonucleotides according to Watson and Crick base-pairing rules. The robustness of PNA oligomers and ease of synthesis have made them an attractive platform to encode small or macromolecules for microarraying purposes and other applications based on programmable self assembly. A cornerstone of these endeavors is the orthogonality of PNAsynthesis with other chemistries