Photoredox-catalyzed oxytrifluoromethylation of allenes: stereoselective synthesis of 2-trifluoromethylated allyl acetates
作者:Ren Tomita、Takashi Koike、Munetaka Akita
DOI:10.1039/c7cc01759f
日期:——
We have developed novel oxytrifluoromethylation of aryl-substituted allenes by photoredox catalysis. The present photocatalytic system allows direct and stereoselective synthesis of 2-CF3-allyl acetates bearing tetrasubstituted CF3-alkene scaffolds in a single operation. The obtained CF3-allyl acetates can be applied to further functionalization as CF3-containing building blocks.
squaramides were prepared in a straightforward manner and investigated as organocatalysts. The reaction protocol is operationally simple to execute and proceeds with up to 76% enantiomeric excess. Several conditions, additives, catalysts, and substrates have been investigated. The best results were observed with 3-((3,5-bis(trifluoromethyl)phenyl)amino)-4-(((1R,2R)-2-(dipentylamino)cyclohexyl)amino)-cyclobut-3-ene-1
Novel pyrrolidine compounds that are potent and selective inhibitors of PDE4, as well as methods of making the same, are disclosed. Use of the compounds in the treatment of inflammatory diseases and other diseases involving elevated levels of cytokines, as well as central nervous system (CNS) disorders, also is disclosed.
Novel pyrrolidine compounds that are potent and selective inhibitors of PDE4, as well as methods of making the same, are disclosed. Use of the compounds in the treatment of inflammatory diseases and other diseases involving elevated levels of cytokines, as well as central nervous system (CNS) disorders, also is disclosed.
Controllable Access to Furans and Dihydrofurans through Cyclization/Coupling of Internal Acetylenic β‐Ketoesters with Aryl Bromides
作者:Bartosz Bisek、Wojciech Chaładaj
DOI:10.1002/adsc.202200686
日期:2022.12.20
Pd-catalyzed tandem cyclization/coupling of internal β-propargylic-β-ketoesters with (hetero)aryl bromides is described. Two protocols are established which selectively lead to 2-benzylidene-dihydrofurans, when isomerization is inhibited under mild conditions (temp. ≤40 °C and weak base – K2CO3), or to 2-benzyl-furans when base-induced aromatization is enabled. A catalytic cycle involving oxidative
描述了 Pd 催化的内部 β-炔丙基-β-酮酯与(杂)芳基溴化物的串联环化/偶联。建立了两种方案,当异构化在温和条件下(温度≤40 °C 和弱碱 – K 2 CO 3)被抑制时,选择性地产生 2-亚苄基-二氢呋喃,或在碱诱导芳构化时产生 2-苄基-呋喃已启用。基于详细的实验和理论研究,提出了涉及氧化加成、用炔取代溴化物、限速反选择性5-exo-dig氧环化随后氧鎓中间体快速去质子化和还原消除的催化循环。