A highly efficient group-assisted purification method for the synthesis of poly-functionalized pyrimidin-5-yl-pyrroles via one-pot four-component domino reaction

Regio- and Diastereoselective Vicinal Aminobromination of Electron Deficient Olefins via Phosphorus-Based GAP Protocol

Chemical synthesis based on Group-Assisted Purification chemistry (GAP) has been prolifically used as a powerful, greener and ecofriendly tool so far. Herein, we report hypervalent iodine (III) mediated regio- and diastereoselective aminobromination of electron-deficient olefins using group-assisted purification (GAP) method. By simply mixing the GAP auxiliary-anchored substrates with TsNH2-NBS as nitrogen/bromine sources and PhI(OAc)2 as a catalyst, a series of vicinal bromoamines with multifunctionalities were obtained in moderate to excellent yields (53-94%). The vicinal bromoamines were obtained without column chromatography and/or recrystallization simply by washing the crude mixtures with cosolvents and thus avoiding wastage of silica, solvents, time, and labor. The GAP auxiliary is recyclable and reusable.

Hypervalent Iodine (III) Catalyzed Regio- and Diastereoselective Aminochlorination of Tailored Electron Deficient Olefins via GAP Chemistry

Herein, we report a protocol for highly efficient hypervalent iodine (III) mediated, group-assisted purification (GAP) method for the regioselectivities and stereoselective aminochlorination of electron-deficient olefins. A series of vicinal chloramines with multifunctionalities were acquired in moderate to excellent yields (45-94%), by merely mixing the GAP auxiliary-anchored substrates with dichloramine T and tosylamide as chlorine/nitrogen sources and iodobenzene diacetate as a catalyst. The vicinal chloramines were obtained without any column chromatographic purification and recrystallization simply by washing the reaction mixture with a minimum amount of common inexpensive solvents and thus avoiding wastage of silica, solvents, time, and labor. The GAP auxiliary is recyclable and reusable. This strategy is easy to handle, cost-effective, greener, sustainable, environmentally benign, and mostly suitable for the syntheses of vicinal haloamines from various electron-deficient alkenes.

Selective synthesis of tetrahydroimidazo[1,2-a]pyridine and pyrrolidine derivatives via a one-pot two-step reaction

In the presence of triethylamine, the addition reaction of substituted α-amino acid alkyl esters with dialkyl but-2-ynedioate afforded active β-enamino esters, which in turn reacted with aromatic aldehydes and malononitrile to give tetrahydroimidazo[1,2-a]pyridine derivatives in moderate yields.

Recent applications of barbituric acid in multicomponent reactions

This review aims to show representative examples of multicomponent reactions utilizing barbituric acid in the synthesis of various heterocyclic structures.

An efficient catalyst-free chemoselective multicomponent reaction for the synthesis of pyrimidine functionalized pyrrolo-annelated derivatives

An efficient catalyst-free, one-pot multicomponent reaction has been developed for the synthesis of pyrimidine functionalized pyrrolo-annelated derivatives. The method offers easy and column free separation, mild reaction conditions and high yields.

A facile approach to the synthesis of structurally diverse 6,8a-dihydropyrido[2,3-d]pyrimidine derivatives via a three-component domino reaction

A concise and efficient approach to the synthesis of structurally diverse 6,8a-dihydropyrido[2,3-d]pyrimidine derivatives has been accomplished for the first-time by a three-component reaction involving alkylsulfonyl acetonitrile, an aromatic aldehyde, and 6-aminouracil.