DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives
作者:Mrinal K. Bera、Rimpa De、Antony Savarimuthu、Tamal Ballav、Pijush Singh、Jayanta Nanda、Avantika Hasija、Deepak Chopra
DOI:10.1055/s-0040-1707909
日期:2020.10
A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondarypropargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer–Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy
Reaction rate differences between organotrifluoroborates and boronic acids in BINOL-catalyzed conjugate addition to enones
作者:Bailey Brooks、Noemi Hiller、Jeremy A. May
DOI:10.1016/j.tetlet.2021.153412
日期:2021.10
has been successfully employed in combination with trifluoroborate reagents for novel organic transformations over the last decade. However, no experimental rate studies of these reactions have been reported. Herein we report Hammett plot analysis of the organocatalyzed enantioselective conjugateaddition of alkenyl, aryl, and heteroaryltrifluoroborate salts to chalcone derivatives with substitution
Totally 38 aryl E 2-propen-1-ones including nine substituted styryl 4-iodophenyl ketones have been synthesised using solvent-free SiO2-H3PO4 catalyzed Aldol condensation between respective methyl ketones and substituted benzaldehydes under microwave irradiation. The yields of the ketones are more than 80%. The synthesised chalcones were characterized by their analytical, physical and spectroscopic
ABSTRACT A new, rapid and efficient method for the synthesis of α,β-unsaturatedketones under microwave irradiation conditions is described. The process involves the reaction of acetals with aryl ketones in the absence of solvent using Lewis acids as catalysts under microwave irradiation to afford the α,β-unsaturatedketones in good to excellent isolated yields. The reaction mechanism is briefly discussed
Polyaniline coated on celite, a heterogeneous support for palladium: applications in catalytic Suzuki and one-pot Suzuki–aldol reactions
作者:Heta A. Patel、Arun L. Patel、Ashutosh V. Bedekar
DOI:10.1039/c6nj02402e
日期:——
Particles of celite were coated with polyaniline, characterized and used as a support for heterogenization of palladium metal ions. The prepared heterogeneous palladium catalysts were screened for Suzuki–Miyaura and one-pot Suzuki–aldol reactions with high conversions. The process of heterogenization on celite reduces the PANI consumption ten-fold when anchoring palladium ions onto the support. The