A catalyst, solvent, work-up and column free synthesis of chromenopyranpyrazoles via multicomponent cascade reaction has been achieved with high stereoselectivity. This novel reaction creates two N–C, two C–C and one O–C bonds through a domino process for the construction of three new rings and three contiguous stereogenic centers.
Solid-State Melt Reaction for the Domino Process: Highly Efficient Synthesis of Fused Tetracyclic Chromenopyran Pyrimidinediones Using Baylis−Hillman Derivatives
A solid-state melt reaction (SSMR) has been demonstrated via a dominoprocess for the synthesis of tetracyclic chromenopyran pyrimidinedione frameworks using Baylis−Hillman derivatives through in situ formation of an olefin followed by an intramolecular [4 + 2] cycloaddition reaction sequence. The tetracyclic frameworks were obtained without using catalyst and solvent in a highly stereoselective and
One-Pot Synthesis of Benzothiazole-Tethered Chromanones/Coumarins via Claisen Rearrangement Using the Solid State Melt Reaction
作者:Manickam Bakthadoss、Raman Selvakumar
DOI:10.1021/acs.joc.5b02920
日期:2016.4.15
A novel protocol has been successfully established for the efficient synthesis of benzothiazole-tethered chromanone/coumarin scaffolds via Claisenrearrangement using a solid state melt reaction in a one-pot manner. Benzothiazole formation and Claisenrearrangement involve the cleavage of S–S and C–O bonds and formation of C–S, C═N, and C–C bonds in a single operation without using a catalyst or solvent
A simple and convenient synthetic route for the synthesis of tricyclic chromeno[4,3-b]pyrrolidine frameworks using Baylis-Hillman bromides involving in situ formation of an imine, decarboxylation and a [3+2] cycloaddition sequence is described. (C) 2007 Elsevier Ltd. All rights reserved.