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
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。
Enantioselective allylic substitution of Morita–Baylis–Hillman adducts catalyzed by planar chiral [2.2]paracyclophane monophosphines
作者:Tang-Zhi Zhang、Li-Xin Dai、Xue-Long Hou
DOI:10.1016/j.tetasy.2007.08.005
日期:2007.8
Planar chiral [2,2]cyclophane monophosphines are efficient catalyst in the reaction of Morita–Baylis–Hillmanadducts with phthalimide. The corresponding allylicsubstituted products were afforded in high yields and in good to moderate ee.
The Importance of Electrostatic Interactions in the Stereoselective 1,3-Dipolar Cycloadditions of Nitrones to Chiral Allyl Ethers: An Experimental and Force Field Approach
The 1,3-dipolar cycloaddition of formaldehyde N-benzylnitrone with β′-alkoxy- and γ-alkoxy-α,β-unsaturated esters was investigated. The stereochemical outcome of these reactions was nicely rationalized on the basis of an interpretation of the inside alkoxy theory emphasizing the electrostatic interactions in the reaction TS. The force field approach previously developed for evaluating the stereoselection
Aziridination of alkenes using 3-acetoxyaminoquinazolin-4(3H)ones: nucleophilic attack by the acetoxyamino group on ester-substituted allylic alcohols
作者:Robert S. Atkinson、John Fawcett、David R. Russell、Paul J. Williams
DOI:10.1039/c39940002031
日期:——
Allylic alcohols 5 and 7 and their acetates 6 and 8 are aziridinated using 3-acetoxyaminoquinazolinone 1; the preferred sense of diastereoselection in aziridination of 5 is inverted in aziridination of its acetate 6 whereas the preferred sense of diastereoselection from 7 is retained in aziridination of its acetate 8; this is interpreted as evidence for nucleophilic attack by the acetoxyamino nitrogen of 1 on the alkene with hydrogen bonding between the hydroxyl and N-acetoxy group present in aziridination of 5 but absent in the case of 7.