Direct Transformation of Baylis-Hillman Acetates into N-Substituted Quinolones through an SN2′ → SNAr → (Δ3,4-Δ2,3 Shift) → Oxidation Sequence
作者:Muraleedharan Kannoth Manheri、John Napoleon
DOI:10.1055/s-0030-1260189
日期:2011.10
SN2′-SNAr cyclization in the presence of alkyl or aralkyl amines, Baylis-Hillman acetates gave the corresponding 1,2-dihydroquinolines, which on simple exposure to light and oxygen afforded the corresponding 4- and 2-quinolones through sensitized oxidation or a Δ³,4-Δ²,³ shift → oxidation cascade. The mechanism of the oxidation step, the stabilities of the 1,2- and 1,4-dihydroquinolines in solution and
当在烷基或芳烷基胺存在下进行串联S N 2'-S N Ar环化反应时,Baylis-Hillman乙酸酯可得到相应的1,2-二氢喹啉,将其简单地暴露于光和氧气下可得到相应的4-和2喹诺酮类化合物通过敏化氧化或Δ³,4-- Δ² ,³转变→氧化级联反应。讨论了氧化步骤的机理,溶液中和固态的1,2-和1,4-二氢喹啉的稳定性以及关键中间体向已知治疗剂的合成工艺。 抗生素-环化-喹啉-自由基反应-光氧化
Enantioselective Allylic Substitution of Morita-Baylis-Hillman Adducts Catalyzed by Chiral Bifunctional Ferrocenylphosphines
A series of air-stable chiralferrocenylphosphines (LB1–LB4) were prepared and used in the asymmetric allylicsubstitution of Morita–Baylis–Hillman (MBH) adducts with phthalimide under mild reaction conditions; the (R,SFc)-ferrocenylphosphine LB4 afforded the desired amination products 3 in moderate yields with excellent enantioselectivities. The absolute configuration of 3o was confirmed by X-ray
Efficient Transformation of Alkyl 3-nitro-5-(aryl/alkyl)isoxazole-4-carboxylates into 3-amino- and 3-hydrazinyl-5-aryl/alkyl-isoxazole-4-carboxylates in Aqueous Solution
作者:Sushobhan Mukhopadhyay、Dinesh S. Barak、Ilesha Avasthi、Sanjay Batra
DOI:10.1002/adsc.201700881
日期:2017.11.23
An efficient protocol for transforming alkyl 3‐nitro‐5‐(aryl/alkyl)isoxazole‐4‐carboxylates into 3‐amino‐ and 3‐hydrazinyl‐5‐aryl/alkyl‐isoxazole‐4‐carboxylates is described. The reaction that is carried out in aqueous acetonitrile solution generally afford the products without any chromatographic purification. Investigations with the substrate scope reveal that this protocol is compatible only when
Efficient and stereoselective rearrangement catalyzed by only one mole-percent gold(I) chloride/silver(I) trifluoromethanesulfonate of Baylis-Hillman acetates afforded 2-(acetoxymethyl)alk-2-enoates under mild reaction conditions in good to high yields with 100% E-selectivity. For cyclohex-2-enone-derived Baylis-Hillman acetates, the reaction gave 2-alkylidenecyclohex-3-enones in good yields.
Synthesis of 3,4,5-Trisubstituted Isoxazoles from Morita-Baylis-Hillman Acetates by an NaNO<sub>2</sub>/I<sub>2</sub>-Mediated Domino Reaction
作者:Shashikant U. Dighe、Sushobhan Mukhopadhyay、Shivalinga Kolle、Sanjeev Kanojiya、Sanjay Batra
DOI:10.1002/anie.201504529
日期:2015.9.7
3‐nitro‐5‐(aryl/alkyl)isoxazole‐4‐carboxylates is described. In a cascade event, initial Michael addition of NaNO2 to the MBH acetate furnishes the allylnitro intermediate which undergoes I2‐catalyzed oxidative α‐CH nitration of the nitromethyl subunit followed by [3+2] cycloaddition to afford the title compounds. Structural elaborations of these highly substituted isoxazoles by SNAr reactions and
本文描述了一种有效的NaNO 2 / I 2介导的Morita-Baylis-Hillman(MBH)乙酸盐单酯转化为3-硝基--5-(芳基/烷基)异恶唑-4-羧酸烷基酯的方法。在一个级联事件,初始迈克尔加成纳米2到MBH醋酸配料其经历我的allylnitro中间2催化的氧化α-C 的硝基甲基亚基h的硝化,接着[3 + 2]环加成,得到标题化合物。这些高度取代的异恶唑通过S N Ar反应和氢解进行结构精制可以得到有用的产品。