Boron Trifluoride Mediated Ring-Opening Reactions of trans-2-Aryl-3-nitro-cyclopropane-1,1-dicarboxylates. Synthesis of Aroylmethylidene Malonates as Potential Building Blocks for Heterocycles
摘要:
trans-2-Aryl-3-nitro-cyclopropane-1,1-dicarboxylates, upon treatment with BF3 center dot OEt2, undergo ring-opening rearrangement and the Nef reaction to give aroylmethylidene malonates. The products are found to be potential precursors for heterocycles, such as imidazoles, quinoxalines, and benzo[1,4]thiazines.
practical phosphine‐catalyzed vicinal difunctionalization of β‐fluoroalkyl α,β‐enones with TMSN3 has been developed. Using dppb as the catalyst, the reaction worked efficiently to yield various β‐amino α‐diazocarbonyl compounds in high yields (up to 94 %). This work marks the first efficient construction of α‐diazocarbonyl compounds by phosphine catalysis. Meanwhile, the asymmetric variant induced by the
A series of new 2H-benzo[1,4]thiazine derivatives were synthesized from aroylmethylidene malonates and o-aminothiophenols by condensation/cyclization methodology in order to evaluate their COX-2 inhibitory activity. In-silico studies indicated that among the synthesized compounds, 5i could serve as a potential candidate for the task. So, compound 5i was taken as a model ligand for in vitro studies
Lewis Acid-Catalyzed Conjugate Addition−Cyclization Reactions of Ethenetricarboxylates with Substituted Propargyl Alcohols: Stereoselectivity in the Efficient One-Pot Synthesis of Methylenetetrahydrofurans
propargyl alcohols 4 with ZnBr2 at 80−110 °C led to (Z)-silicon-substituted products stereoselectively. Reaction of 1 and γ-ester-substituted propargyl alcohol 7 in the presence of various Lewis acids gave ester-substituted methylenetetrahydrofurans stereoselectively. Interesting Lewis acid dependency on stereoselectivity for the reaction of 7 was found. Reaction of α-substituted propargyl alcohols
Synthesis of 2,4,5-trisubstituted oxazoles through tin(<scp>iv</scp>) chloride-mediated reaction of trans-2-aryl-3-nitro-cyclopropane-1,1-dicarboxylates with nitriles
作者:Thangavel Selvi、Kannupal Srinivasan
DOI:10.1039/c4cc04764h
日期:——
trans-2-Aryl-3-nitro-cyclopropane-1,1-dicarboxylates when reacted with nitriles in the presence of tin(IV) chloride afford 2,4,5-trisubstituted oxazoles in good to excellent yields. The reactions take place through in situ generation of aroylmethylidene malonates from the cyclopropanes, followed by conjugate addition of nitriles to the malonates to form nitrilium ion intermediates and subsequent cyclisation
Boron Trifluoride-Promoted Indium(III) Triflate-Catalyzed Sequential One-Pot Synthesis of (1,2-Diaryl-2-oxoethyl)malonates from<i>trans</i>-2-Aryl-3-nitrocyclopropane-1,1-dicarboxylates and Activated Arenes
作者:Thangavel Selvi、Kannupal Srinivasan
DOI:10.1002/adsc.201500143
日期:2015.6.15
A sequential one‐pot synthesis of Michael adducts of aroylmethylidenemalonates with activated aromatics is described. The method involves treatment of trans‐2‐aryl‐3‐nitro‐cyclopropane‐1,1‐dicarboxylates with boron trifluoride etherate to form aroylmethylidenemalonates in situ and then addition of activated aromatics such as indoles, carbazole, pyrrole, thiophenes, methoxybenzenes and benzodioxole