Palladium(II)-Catalyzed Ortho Arylation of 2-Phenoxypyridines with Potassium Aryltrifluoroborates via C−H Functionalization
摘要:
An efficient synthesis of ortho-arylated 2-phenoxypyridines catalyzed by palladium acetate is described. Treatment of 2-phenoxypyridines with two and a half equivalents of potassium aryltrifluoroborate and 10 mol % of Pd(OAc)(2) in the presence of two equivalents of Ag(2)CO(3), one equivalent of p-benzoquinone (BQ), and four equivalents of DMSO with (or without) H(2)O at 130-140 degrees C for 48 h in dried CH(2)Cl(2) gave the ortho-arylated 2-phenoxypyridines in modest to excellent yields. p-Benzoquinone is found to be an important ligand and co-oxidant for the transmetalation reductive elimination step in the catalytic reaction. The investigation of kinetic isotope effect (k(H)/k(D)) is determined to be 5.25, which indicates that C H bond cleavage occurs in the rate-determining step. One of the arylated compounds, 2-(4'-nitrobiphenyl-2-yloxy)pyridine, was treated with methyl trifluoromethanesulfonate and subsequently sodium methoxide to give the 2-(4-nitrophenyl)phenol in 79% yield, demonstrating that pyridine is a removable directing group.
Quinoline, isoquinoline, quinoxaline, and quinazoline derivatives were synthesized using microwave-assisted synthesis and their CB1/CB2 receptor activities were determined using the [35S]GTPγS binding assay. Most of the prepared quinoline, isoquinoline, and quinoxalinyl phenyl amines showed low-potency partial CB2 receptor agonists activity. The most potent CB2 ligand was the 4-morpholinylmethanone
使用微波辅助合成法合成喹啉,异喹啉,喹喔啉和喹唑啉衍生物,并使用[ 35 S]GTPγS结合测定法测定其CB1 / CB2受体活性。大部分制备的喹啉,异喹啉和喹喔啉基苯胺均显示出低效的部分CB2受体激动剂活性。最有效的CB2配体是4-吗啉基甲酮衍生物(化合物40e)(-log EC 50 = 7.8;E max = 75%)。异喹啉-1-基(3-三氟甲基-苯基)胺(化合物26c)是一种高效的CB2激动剂(-log EC 50 = 5.8; E max = 128%)。在这些研究中,没有发现明显的CB1受体激活或失活,除了40e表现出弱的CB1激动剂活性(CB1-log EC 50 = 5.0)。这些配体用作开发选择性CB2受体激动剂的新型模板。
Rhodium‐Catalyzed Enantioselective Oxidative [3+2] Annulation of Arenes and Azabicyclic Olefins through Twofold C−H Activation
作者:Ruijie Mi、Guangfan Zheng、Zisong Qi、Xingwei Li
DOI:10.1002/anie.201911086
日期:2019.12.2
mostly limited to ortho selectivity. Activation of both ortho and meta C-H bonds constitutes a particularly important strategy for annulation, but has rarely been studied in enantioselective systems. Reported herein is rhodium(III)-catalyzed asymmetric [3+2] transannulation of arenes with 7-azabenzonorbornadienes. Two distinct classes of arenes have been identified as substrates, and the coupling proceeded
The use of substituted amides for modulating the activity of 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) and the use of these compounds as pharmaceutical compositions, are described. Also a novel class of substituted amides, their use in therapy, pharmaceutical compositions comprising the compounds, as well as their use in the manufacture of medicaments are described. The present compounds are modulators and more specifically inhibitors of the activity of 11βHSD1 and may be useful in the treatment of a range of medical disorders where a decreased intracellular concentration of active glucocorticoid is desirable.
A Direct C2-Selective Phenoxylation and Alkoxylation of Quinoline <i>N</i>
-Oxides with Various Phenols and Alcohols in the Presence of <i>H</i>
-Phosphonate
A practical and efficient method for the synthesis of 2-aroxy(alkoxy)quinolines has been developed, via direct cross-dehydrogenativecoupling reaction between quinoline N-oxides and readily available phenols and alcohols in the presence of H-phosphonate and CCl4 under mild conditions.