Iron-catalyzed multicomponent reaction of cycloketone oxime esters, alkenes, DABCO·(SO2)2 and trimethylsilyl azide

An iron-catalyzed four-component reaction of cycloketone oxime esters, alkenes, DABCO·(SO2)2 and trimethylsilyl azide (TMSN3) is described. This multicomponent radical transformation presents excellent regio- and chemo-selectivity, leading to a range of...

Simple inorganic base promoted polycyclic construction using mucohalic acid as C3 synthon: Synthesis and AIE probe application of benzo[4,5]imidazo[1,2-a]pyridines

A transition metal-free and efficient synthesis of fused azapolycycles via multicomponent reaction has been developed from mucohalic acid as C3 synthon. The reaction promoted by simple inorganic base K2CO3 gives...

Eco-friendly Synthesis of Some New Benzylidene-iminothiazolyl-pyrazol-3-ol Derivatives via One-Pot Multicomponent Reaction and Evaluation of Antioxidant Activities

In present work, one-pot multicomponent reaction (MCR) route for the synthesis of benzylideneiminothiazolyl- pyrazol-3-ol derivatives (5a-p) by reacting ethyl cyanoacetate (1), substituted benzaldehyde (2a-c), thiosemicarbazide (3) and substituted phenacyl bromide (4a-g). This reaction proceeds by using bleaching earth clay (BEC) (pH 12.5) in PEG-400 as a green reaction media. All the synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral data. The pharmacological investigation of the synthesized compounds suggest that most of them showed good antioxidant activity.

Enantioselective Au(I)-Catalyzed Multicomponent Annulation via Tethered Counterion-Directed Catalysis

Gold(I) complexes of a new chiral phosphoric acid functionalized phosphine of the CPA-Phos series enable the enantioselective multicomponent reactions between aldehydes, hydroxylamines and cyclic yne-enones, leading to 3,4-dihydro-1H-furo[3,4-d][1,2]oxazines. This represents the first example of highly enantioselective multicomponent reaction in gold(I) catalysis. The reactions proceed at low catalyst loading, provide high yields, total diastereoselectivity and enantiomeric excesses up to 99%. Silver-free conditions can be applied. The method has a very broad scope, as it applies to both aliphatic and aromatic aldehydes and hydroxylamines, to a variety of cyclic yne-enones, as well as to yne-enone derived oximes. DFT calculations are reported that enlighten the enantiocontrol pathway.