排序方式: 共有52条查询结果,搜索用时 390 毫秒
31.
A Pd-catalyzed decarboxylative coupling of substituted benzoic acids with phenylboronic acid has been developed. Under the optimized conditions, a variety of substituted benzoic acids were found to undergo decarboxylative coupling with various phenylboronic acids to give the desired unsymmetrical biaryls in good yields.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
32.
Total Synthesis of Resveratrol‐Based Natural Products Using a Palladium‐Catalyzed Decarboxylative Arylation and an Oxidative Heck Reaction 下载免费PDF全文
Felix Klotter Prof. Dr. Armido Studer 《Angewandte Chemie (International ed. in English)》2014,53(9):2473-2476
Controlled access to resveratrol‐based natural products is offered by a novel, modular concept. A common building block readily available on a large scale serves as the starting material for the introduction of structurally important aryl groups by a Pd‐catalyzed decarboxylative arylation and an oxidative Heck reaction with good yields and high stereoselectivity. The modular approach is convincingly documented by the successful synthesis of three racemic resveratrol‐based natural products (quadrangularin A, ampelopsin D, and pallidol). 相似文献
33.
Mukka Satish Kumar Marri Venkateswarlu Purugula Venkanna Pondichery Kuppuswamy Saiprakash 《合成通讯》2013,43(19):2251-2258
An efficient and safe method for nitration of aromatic compounds and decarboxylative nitration of α,β-unsaturated acids was developed using trichloroisocyanuric acid (TCICA)/dimethylformamide (DMF) in the presence of NaNO2. The reaction times of conventional protocol reduced from 8–10 h to 1.0–1.5 h (60–90 min) under sonication, even though the yields are comparable under both the conditions. 相似文献
34.
35.
《Tetrahedron》2019,75(36):130493
Photoinduced decarboxylative radical additions of 5-membered alicyclic α-amino acids bearing a (2-phenyl)benzoyl protective group to acrylonitrile under mild organic photoredox catalysis conditions furnished γ-amino acid derivatives with high retention of chirality via the memory of chirality (MOC) strategy. The retention of chirality in the photoinduced decarboxylation was strongly dependent on the structure of the alicyclic α-amino acids and alkenes. To the best of our knowledge, this is the first example of the decarboxylative intermolecular radical addition to alkenes with retention of chirality at the position of radical generation using the MOC strategy. 相似文献
36.
Yaping Li Shihao Chen Ming Wang Xuefeng Jiang 《Angewandte Chemie (International ed. in English)》2020,59(23):8907-8911
A straightforward multicomponent decarboxylative cross coupling of redox‐active esters (N‐hydroxyphthalimide ester), sodium dithionite, and electrophiles was established to construct sterically bulky sulfones. The inorganic salt sodium dithionite not only served as the sulfur dioxide source, but also acted as an efficient radical initiator for the decarboxylation. Notably, diverse naturally abundant carboxylic acids and artificially prepared carboxyl‐containing drugs with multiple heteroatoms and sensitive functional groups successfully underwent this decarboxylative sulfonylation to provide sterically bulky tertiary sulfones. Mechanistic studies further demonstrated that decarboxylation was the rate‐determining step and occurred via a single‐electron transfer (SET) process with the assistance of sodium dithionite. 相似文献
37.
邻苯二甲酰亚胺羧酸酯的自由基脱羧是产生碳自由基的一类重要方法. 开发了一类路易斯碱-硼自由基促进的邻苯二甲酰亚胺羧酸酯的自由基脱羧新方式, 产生的烷基自由基经过加成到缺电子烯烃上或者进一步还原得到Giese反应和Barton脱羧产物. 该反应条件温和, 适用范围广泛, 多种一级、二级和三级烷基羧酸包括具有生物活性的天然产物和药物分子都能够较好地适用, 为邻苯二甲酰亚胺羧酸酯的自由基脱羧提供了无过渡金属参与的具有普适性的新方式. 相似文献
38.
2,6-Bis(arylmethylidene)cyclohexanones undergo a regioselective 1,3-dipolar cycloaddition reaction with the azomethine ylide derived from isatin and sarcosine by a decarboxylative route affording a series of 1-N-methyl-spiro[2.31]oxindole-spiro[3.211]611-arylmethylidenecyclohexanone-4-aryl-pyrrolidines which were further annulated to give a series of novel 1-N-methyl-spiro[2.31]oxindole-spiro[3.711](311-aryl)Δ111,711a-hexahydro-2H-indazole-4-aryl-pyrrolidines. The structures of which were established by spectroscopic techniques as well as single crystal X-ray analysis. 相似文献
39.
Dr. Yang Gao Yang Ou Prof. Dr. Lukas J. Gooßen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(37):8709-8712
Acrylic acid is presented as an inexpensive, non-volatile vinylating agent in a palladium-catalyzed decarboxylative vinylation of aryl halides. The reaction proceeds through a Heck reaction of acrylic acid, immediately followed by protodecarboxylation of the cinnamic acid intermediate. The use of the carboxylate group as a deciduous directing group ensures high selectivity for monoarylated products. The vinylation process is generally applicable to diversely substituted substrates. Its utility is shown by the synthesis of drug-like molecules and the gram-scale preparation of key intermediates in drug synthesis. 相似文献
40.
Sijing Xue Dr. Alexander Lücht Dr. Jordi Benet-Buchholz Prof. Arjan W. Kleij 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(39):10107-10114
The challenging metal-catalyzed asymmetric synthesis of highly functional quaternary carbon centers using decarboxylative C(sp3)−C(sp3) bond formation reactions is reported. The key substrate, a vinyl cyclic carbonate, is activated to provide concomitantly both the requisite nucleophile (by formal umpolung) and electrophile reaction partner preceding the asymmetric cross-coupling process. A wide screening of reaction conditions, additives and catalyst precursors afforded a protocol that gave access to a series of compounds featuring densely functionalized, elusive quaternary carbon stereocenters in appreciable yield and with enantiomeric ratios (er's) of up to 90 : 10. 相似文献