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.
A facile synthesis of chromeno[4,3-b]pyrroles derived from allyl derivatives of Baylis–Hillman adducts through intramolecular 1,3-dipolar cycloaddition using ultrasonication
作者:Ekambaram Ramesh、Raghavachary Raghunathan
DOI:10.1016/j.tetlet.2007.12.066
日期:2008.2
Synthesis of a series of chromene[4,3-b]pyrroles has been accomplished through an intramolecular1,3-dipolarcycloaddition reaction of an azomethine ylide with the dipolarophile derivedfrom Baylis–Hillman adducts. Improved yields of the same products were obtained when the reaction was carried out under ultrasonication.
一系列亚甲基[4,3- b ]吡咯的合成是通过甲亚胺叶立德与衍生自Baylis-Hillman加合物的双极性亲核剂的分子内1,3-偶极环加成反应完成的。当反应在超声下进行时,获得相同产物的提高的产率。