One-Pot Stereoselective Synthesis of (<i>Z</i>)-β-Ketoenamides from β-Halo α,β-Unsaturated Aldehydes
作者:Junali Gogoi、Pranjal Gogoi、Romesh C. Boruah
DOI:10.1002/ejoc.201400007
日期:2014.6
β-ketoenamides have been synthesized from their corresponding β-halo α,β-unsaturatedaldehydes. This synthetic methodology provides efficient access to (Z)-β-ketoenamides. The structures of these products have been unambiguously established by single crystal XRD studies. This process is found to be mild and inexpensive. The required β-halo α,β-unsaturatedaldehydes are synthesized from corresponding ketones using
An enantioselective organocatalytic intramolecular Morita–Baylis–Hillman (IMBH) reaction of dienones, and elaboration of the IMBH adducts to fluorenones
作者:Bishnupada Satpathi、Siddhant V. Wagulde、S. S. V. Ramasastry
DOI:10.1039/c7cc02524f
日期:——
An enantioselective organocatalytic intramolecularMorita-Baylis-Hillman (IMBH) reaction of dienones is reported for the first time. This has been achieved by incorporating entropy and synergy considerations during the substrate design. The reaction conditions are thoroughly verified for an efficient synthesis of highly functionalised cyclopenta-fused arenes and heteroarenes in excellent yields and
Phosphine- and water-promoted pentannulative aldol reaction
作者:Bishnupada Satpathi、Lona Dutta、S. S. V. Ramasastry
DOI:10.1039/c8ob03106a
日期:——
intramolecular aldolreaction for the synthesis of an unusual class of cyclopentanoids is described. The reaction of α-substituted dienones tethered with ketones in the presence of tributylphosphine and water provided aldols. The role of water was realised to be crucial for this transformation. Furthermore, isotopic labeling experiments provided vital information about the reaction mechanism.
β-halo α,β-unsaturated aldehydes by a microwave-assisted Knoevenagel reaction. The β-halo-α,β-unsaturated aldehydes were, in turn, efficiently synthesized from the corresponding ketones by a Vilsmeier formylation reaction. The protocol was used to synthesize several novel steroidal and nonsteroidal fused 2-aminopyridine derivatives. 2-Aminopyridines were synthesized from β-halo α,β-unsaturated aldehydes
Palladium-Catalyzed One-Pot Sonogashira Coupling,<i>exo</i>-<i>dig</i>Cyclization and Hydride Transfer Reaction: Synthesis of Pyridine-Substituted Pyrroles
作者:Kommuri Shekarrao、Partha Pratim Kaishap、Sanjib Gogoi、Romesh C. Boruah
DOI:10.1002/adsc.201401117
日期:2015.4.13
An efficient palladium(II)‐catalyzed method for the synthesis of alkylated pyridine‐substituted pyrroles has been developed by a one‐pot three component reaction of β‐bromovinyl aldehydes, primary amines and 2‐alkynylpyridines in good yields. The reactions can also provide an efficient route to 2‐picolinoylpyrroles by slightly altering the reaction conditions.