Three-component condensations, copper

Ahmadi, S. J., Hosseinpour, M., and Sadjadi, S. 2011. Nanocrystalline copper(II) oxide-catalyzed one-pot synthesis of imidazo[l,2-a]quinoline and quinolino[l,2-a]quinazo-line derivatives via a three-component condensation. Synth. Commun. 41(3) 426-435. 

N. Gommermann, P. Knochel, Chem.-Eur. J. 2006, 12, 4380-4392. Practical highly enantioselective synthesis of propargylamines through a copper-catalyzed one-pot three-component condensation reaction. 

Copper oxide NPs [72] showed excellent catalytic activity through three-component condensation reaction of aldehydes, malononitrile, and 4-hydroxycoumarin for the synthesis of 3,4-dihyropyrano[c]chromenes in water as a reaction medium in excellent yields and very short reaction times (Scheme 5.25). 

Aminopyridines can be used in other ways copper-catalysed interaction with diazo-ketones and three-component reactions involving an isonitrile and an aldehyde also give imidazo[l,2-a]pyridines such condensations can be promoted using an ionic liquid" or scandium triflate with microwave heating." In the former route, 2-substituted products result and from the latter, 3-aminoimidazo[l,2-a]pyridines are formed. 

Recently, Ma et al. developed a three-component reaction for the synthesis of 2-A -substituted benzothiazoles 107 via the copper-catalyzed coupling of 2-iodoanilines, carbon disulfide, and secondary amines (Scheme 3.56) [149]. In these reactions, the condensation of CS with an amine in the presence of a base generates dithiocarbamate salts XXXV, which undergo coupling with 2-iodoanilines to give XXXVI and subsequent intramolecular condensation and elimination to afford the substituted benzothiazoles 107. 

D. Ma, X. Lu, L. Shi, H. Zhang, Y. Jiang, X. Liu, Angew. Chem. Int. Ed. 2011, 50, 1118-1121. Domino condensation/S-arylation/heterocyclization reactions copper-catalyzed three-component synthesis of 2-V-substituted benzothi azoles. 

Kobayashi and coworkers showed that Lewis add surfactant-combined catalysts such as scandium tris(dodecyl sulfate), Sc(03SCi2H25)3, or copper bis(dodecyl sulfate), Cu(03SCi2H25)2, were efficient catalysts for the three-component Mannich-type reaction, with 73-95% yield being obtained in neat water.Neutral salts such as sodium triflate and sodium iodide catalyzed the condensation reaction in water between preformed imines and silicon enolates, or the three-component Mannich-type reaction using aromatic amines, with 49-93% yields and 0-80% diastereoselectivities. Mechanistic studies indicated that both sodium triflate and the Mannich adduct itself cooperatively promote the reaction. 

Kim Y, Kumar MR, Park N, Heo Y, Lee S (2011) Copper-catalyzed, one-pot, three-component synthesis of benzimidazoles by condensation and C-N bond formatiotL J Org Chem 76(23) 9577-9583... 

Ma et al. developed a copper-catalyzed cascade condensation/S-arylation/hetero-cyclization for the three-component synthesis of 2-iV-substituted benzothiazoles 113 from amines, carbon disulfide, and 2-haloanilines (Scheme 5.75) [78]. The first step in this process is the reaction between amine and carbon disulfide in the presence of bases to form dithiocarbamate salt A. Then, the in situ-generated A undergoes... 

The challenge of three-component synthesis of prostaglandines has been met by Ryoji Noyori et /. with extraordinary success. The assembly of the "lower" ((d) and the "upper" (a) side chain is accomplished in a "one-pot" protocol. The (D-side chain is attached by addition of (5)-/raiw-3-terr-butyldimethylsiIyIoxy-l-octenyllithium complexed with one equivalent of dimethylzinc or, alternatively, with copper iodide and tributylphosphine. To install the a-chain, the zinc enolate formed in the preceding step is directly condensed with the functionalized cts-allylic or propargylic part, whereas the copper enolate has to be added in the presence of triphenyltin chloride and hexamethylphosphoric acid triamide (HMPA). ... 

The condensation of acetone with D-ribose, with sulfuric acid as the catalyst, has also been examined in detail.17 The major component is 2,3-O-isopropylidene-D-ribofuranose (59%), together with three minor components l,5-anhydro-2,3-0-isopropylidene-D-ribofuranose (9%), 1,2 3,4-di-O-isopropylidene-a-D-ribopyranose (3%), and 1,2-0-isopropylidene-a-D-ribofuranose (6%). The authors observed that the only marked difference when other catalysts (such as copper sulfate or zinc chloride) were used was the absence of the anhydro compounds. Assuming that the 1-hydroxyl group is equatorial, the preponderance of the 2,3-acetal is consistent with the thermodynamic stability of the isomer having the least number of endo substituents and with the unfavorable interactions between the acetal rings in the 1,2 3,4-diacetal, which possesses a cis-syn-cis arrangement of rings.10... 

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