Sequential three-component one-pot reaction

Type of reaction C-N bond formation Reaction conditions Chloroform, room temperature Synthetic strategy Sequential three-component one-pot reaction Catalyst Catalyst-free... 

Multicomponent reactions have been described for several syntheses of imidazoles. Highly efficient methods for the syntheses of spiroimidazolinones via microwave-assisted three-component one-pot sequential reactions or one-pot domino reactions have been described <06JOC3137>. Multicomponent reactions between 2-aminopyrimidine, aldehydes and isonitriles afforded imidazo[l,2-a]pyrimidines <06TL947>. Two novel one-step microwave mediated syntheses of arrays of 3-iminoaryl-imidazo[l,2-a]pyridines and imidazo[l,2-a]pyridyn-3-ylamino-2-acetonitriles were synthesized by multicomponent reactions under microwave condition in methanol by simply mixing a-aminopyridines, aldehydes, and trimethylsilylcyanide catalyzed by polymer-bound scandium triflate <06TL2989>. 3-Aminoimidazo[l,2-a]pyridines have been synthesized via the multicomponent reaction of aldehydes, isocyanides and 2-aminopyridines in the presence of the ionic liquid l-butyl-3-methylimidazolium bromide [bmim]Br<06TL3031>. 

An interesting one-pot sequential three-component reaction involving the nude-... 

Keywords 1,2-Diaza-1,3-dienes, amines, isocyanates, ethanol, room temperature, sequential three-component reaction, aza-Michael reaction, one-pot synthesis, functionalized 1,3,5-trisubstituted hydantoins... 

In 2008, Sorimachi and Terada reported a relay catalysis using a rhodium hydride complex/Brpnsted acid (129) binary system (Scheme 5.88) [89]. The sequential transformation involves a three-step relayed catalysis, where (1) isomerization of allylamide 130 to enamide A is catalyzed by RhClH(CO)(PPh3)j (2) subsequent isomerization of A to imine B is relayed by 129 and (3) the catalytic sequence is terminated by a carbon-carbon bond forming the reaction of B with a nucleophilic component 131 under 129. This approach enables the generation of reactive imines B from readily available allylamides 130 in a one-pot reaction via tandem isomerization. 

Rolfe A, Young K, Hanson PR. Domino Heck-Aza-Michael reactions a one-pot, sequential three-component approach to l,l-dioxido-l,2-benzisothiazoline-3-acetic acid. Eur. J. Org. Chem. 2008 31 5254-5262. 

Shen L, Zhang J, Cao S, Yu JL, Liu NJ, Wu JJ, Qian XH (2008) One-pot synthesis of trifluoromethyl-containing pyrazoles via sequential Yb(PFO)(3)-catalyzed three-component reaction and IBX-mediated oxidation. Synlett 3058-3062... 

The reaction of an N-acyliminium ion pool with an alkene or alkyne followed by trapping of the resulting carbocation by water leads to the formation of the corresponding carbohydroxylation product. Cationic sequential one-pot, three-component coupling reactions of an N-acyliminium ion can also be accomplished using an electron-rich olefin and a suitable nucleophile that traps the thus-generated cationic intermediate as shown in Scheme 5.17. ... 

The Pd-catalyzed sequential reaction of the three components aryl iodide, alkyl iodide, and arylboronic acid can be performed in a one-pot operation (Scheme 17 and Table 3). ... 

The reactions initiated by the addition of a carbon-carbon multiple bond to the cation pool bring in unique one-pot transformations otherwise difficult to realize, because the reactive carbocations are existing in the solution in relatively high concentration. For example, a sequential one-pot three-component coupling reactions have been developed (Scheme 5) [9, 10]. [4 -f 2] cyclo addition reactions in which an N-acyliminium ion was used as a hetero diene [11], and cationic carbohydroxylation of alkenes and alkynes using the cation pool method [12] were also accomplished. 

S. Matsuoka, Y. Tochigi, K. Takagi, M. Suzuki, Tetrahedron 2012, 68, 9836-9841. Sequential one-pot and three-component reactions of an N-heterocychc carbene to form 4-(l,2,4-triazol-5-ylidene)pyrrolidine-2,5-diones a tandem umpolung/ annulation sequence via deoxy-Breslow intermediates. 

As mentioned previously in this book, the quest for sustainable, atom-economical, and environmentally friendly chemical processes is a big current issue. Besides one-pot, sequential reaction processes (generally catalyzed by either metals or enzymes), multicomponent reactions have become very important [51]. The Petasis reaction, alternatively called Petasis horono Mannich reaction, is a mUd multicomponent reaction, which was reported first by Petasis and Akritopoulou in 1993 [52]. This reaction allows the one-pot three-component condensation of an aryl- or alkylboronic acid, an amine, and an aldehyde (or generally a carbonylic compound) to generate substituted amines at room temperature (Scheme 6.38). 

In 2013, Fox and co-workers reported an enantioselective synthesis of cyclobutanes based on a sequential rhodium-catalysed bicyclobutanation-copper-catalysed homoconjugate addition-enolate trapping reaction. Indeed, a range of enantiomerically enriched functionalised cyclohutanes were constructed through this one-pot three-component process in which t-butyl... 

Therefore, the direct synthesis of cyclic carbonates from olefins instead of epoxides, a so-called one-pot "oxidative carboxylation" of olefins, would be appealing. The oxidative carboxylation synthesis from olefins can be roughly viewed as the coupling of two sequential processes of epoxidation of olefins and CO2 cycloaddition to epoxides formed (Scheme 18). The reaction uses easily available and low-priced chemicals of olefins as substrates and, moreover, preliminary synthesis and separation of epoxides would be avoided. So, the oxidative carboxylation would be a simpler and cheaper carbonate synthesis process with industrial potential from environmental and economic points of view. Although the three-component couplings have been known at least since 1%2 [66], up to date, only a few works have been made on these reactions in contrast to extensive studies on the addition reactions of CO2 to epoxides in ILs as catalyst/or solvent. 

A CuI/DMEDA-catalyzed intramolecular coupling of A-unprotective amidines 181 has been used for assembling 1,2,4-Benzothiadiazine 1,1-dioxides 182, another important class of heterocycles for pharmaceutical design (Scheme 63) [108]. Because the preparation of the amidines 181 could be achieved via a Cul-catalyzed three-component reaction of 1-alkynes, ammonium salts and aryl sulfonyl azides, a more efficient one-pot sequential process has been developed for the synthesis of 182 from these reagents. 

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