Mild Palladium-Catalyzed Cyanation of (Hetero)aryl Halides and Triflates in Aqueous Media
作者:Daniel T. Cohen、Stephen L. Buchwald
DOI:10.1021/ol5032359
日期:2015.1.16
A mild, efficient, and low-temperature palladium-catalyzed cyanation of (hetero)aryl halides and triflates is reported. Previous palladium-catalyzed cyanations of (hetero)aryl halides have required higher temperatures to achieve good catalytic activity. This current reaction allows the cyanation of a general scope of (hetero)aryl halides and triflates at 2–5 mol % catalyst loadings with temperatures
Efficient and Practical Oxidative Bromination and Iodination of Arenes and Heteroarenes with DMSO and Hydrogen Halide: A Mild Protocol for Late-Stage Functionalization
efficient and practical system for inexpensive bromination and iodination of arenes as well as heteroarenes by using readily available dimethyl sulfoxide (DMSO) and HX (X = Br, I) reagents is reported. This mild oxidative system demonstrates a versatile protocol for the synthesis of aryl halides. HX (X = Br, I) are employed as halogenating reagents when combined with DMSO which participates in the present
Structurally Divergent Lithium Catalyzed Friedel-Crafts Reactions on Oxetan-3-ols: Synthesis of 3,3-Diaryloxetanes and 2,3-Dihydrobenzofurans
作者:Rosemary A. Croft、James J. Mousseau、Chulho Choi、James A. Bull
DOI:10.1002/chem.201604031
日期:2016.11.2
first examples of 3,3‐diaryloxetanes are prepared in a lithium‐catalyzed and substrate dependent divergent Friedel–Crafts reaction. para‐Selective Friedel–Crafts reactions of phenols using oxetan‐3‐ols afford 3,3‐diaryloxetanes by displacement of the hydroxy group. These constitute new isosteres for benzophenones and diarylmethanes. Conversely, ortho‐selective Friedel–Crafts reactions of phenols afford
Lithium-Catalyzed Thiol Alkylation with Tertiary and Secondary Alcohols: Synthesis of 3-Sulfanyl-Oxetanes as Bioisosteres
作者:Rosemary A. Croft、James J. Mousseau、Chulho Choi、James A. Bull
DOI:10.1002/chem.201705576
日期:2018.1.19
inexpensive Li catalyst enables chemoselective C-OH activation and thiol alkylation. Oxetane sulfides are formed from various thiols providing novel motifs in new chemical space and specifically as bioisosteres for thioesters due to their similar shape and electronic properties. Under the same conditions, various π-activated secondary and tertiary alcohols are also successful. Derivatization of the oxetane
3-硫烷基-氧杂环丁烷被认为是硫酯或苯硫醚的有前途的新型生物电子等排替代品。一种温和且廉价的 Li 催化剂以 oxetan-3-ols 为原料,能够实现化学选择性 C-OH 活化和硫醇烷基化。氧杂环丁烷硫化物由各种硫醇形成,在新的化学空间中提供新颖的基序,并且由于其相似的形状和电子特性,特别是作为硫酯的生物等排体。在相同条件下,各种π活化的仲醇和叔醇也获得了成功。氧杂环丁烷硫化物连接体的衍生化提供了更多新颖的氧杂环丁烷类别和结构单元。氧杂环丁烷化合物与选定的羰基和亚甲基类似物的关键物理化学性质的比较表明,这些基序适合纳入药物发现工作。
Palladium-catalyzed direct desulfitative C2 arylations of 3-halo-N-protected indoles using (hetero)arenesulfonyl chlorides
作者:Anoir Hfaiedh、Hamed Ben Ammar、Jean-François Soulé、Henri Doucet
DOI:10.1039/c6ob00584e
日期:——
through a direct desulfitative arylation, followed by in situ dehalogenation. While, from 3-bromoindole derivatives, 2-aryl-3-bromoindoles were obtained without debromination, and could be converted into 2,3-diarylindoles through a second palladium coupling. This method allows one to prepare in a few steps a very wide variety of indole derivatives, which are of interest in the synthesis of bioactive molecules