This paper describes the synthesis of a bicyclic β-amino acid scaffold in both pure enantiomeric forms and its application as chiral auxiliary an intramolecular version Ugi multicomponent reaction (U-5C-4CR) to prepare α-amino derivatives d- l-series straightforward very stereoselective manner. The mild conditions required for condensation removal make this method attractive wide range differently structured N-alkylated unalkylated amino derivatives.

This account summarizes the results of studies carried out by authors during last 10 years aimed at expanding utility venerable Passerini and Ugi reactions. Particular emphasis is given to efforts that focus on coupling these processes with post-condensation, intramolecular, aliphatic nucleophilic substitution acyl The methodologies developed in investigations serve as basis for short sequences preparation a diverse number interesting drug-like structures.

A short, two-step approach to the synthesis of diazepane or diazocane systems, based on a Ugi multicomponent reaction followed by subsequent intramolecular SN2 was studied. 1-Sulfonyl tetrahydrobenzo[e]-1,4-diazepin-1-ones 1 were obtained in very high yield through Mitsunobu cyclization. On other hand, aliphatic 1-sulfonyl 1,4-diazepan-5-ones 2 could be employing different cyclization conditions (sulfuryl diimidazole). similar toward rings using hydroxamates as nucleophiles less successful,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleEnantioselective synthesis of the bottom half chlorothricolide. 2. A comparative study substituent effects on stereoselectivity key intramolecular Diels-Alder reactionWilliam R. Roush and Renata RivaCite this: J. Org. Chem. 1988, 53, 3, 710–712Publication Date (Print):February 1, 1988Publication History Published online1 May 2002Published inissue 1 February 1988https://doi.org/10.1021/jo00238a049RIGHTS & PERMISSIONSArticle...

Lipase mediated desymmetrization of a meso-diol (1,2-cyclopentanedimethanol) allows the synthesis both enantiomers some chiral aldehydes, whose behavior in Passerini and Ugi reactions has been explored. Exploiting these two complementary multicomponent coupling them with subsequent cyclization process, we observed that 6 out all 8 possible stereoisomers peptidomimetic pyrrolidines can be obtained good yields. The potential protocols proved by development new efficient antiviral drug telaprevir.

Three-component Passerini condensation of N-Boc-α-aminoaldehydes with various isocyanides and carboxylic acids leads, after Boc-deprotection/transacylation, to complex peptide-like structures containing an α-hydroxy-β-aminoacid unit or, oxidation, α-oxo-β-aminoacid unit.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnantioselective synthesis of the bottom half chlorothricolide. 3. Studies steric directing group strategy for stereocontrol in intramolecular Diels-Alder reactionsWilliam R. Roush, Masanori Kageyama, Renata Riva, Bradley B. Brown, Joseph S. Warmus, and Kevin J. MoriartyCite this: Org. Chem. 1991, 56, 3, 1192–1210Publication Date (Print):February 1, 1991Publication History Published online1 May 2002Published inissue 1 February...

A small library of natural product-like compounds has been assembled by coupling an Ugi multicomponent reaction with two postcondensation transformations, carried out in one-pot fashion: a SN2′ cyclization followed intramolecular Heck reaction.

Abstract Isocyanide‐based multicomponent reactions (I‐MCRs) represent a milestone in combinatorial chemistry. Recently, efforts have been made to include I‐MCRs tandem or sequential pathways synthesise more complex molecules, and the bicyclo[2.2.1]heptene (norbornene) moiety has demonstrated be very versatile scaffold when employed broaden scope of approach, making it perfectly suited for diversity‐oriented synthesis. In addition this, (hetero)norbornane/norbornene shown influence...

A highly diastereoselective Ugi reaction involving a chiral cyclic imine, two enantiomerically pure isocyanides and various carboxylic acids was employed for the synthesis of polyfunctionalized pyrrolidines. Both substrates have been efficiently prepared by chemoenzymatic methodologies from readily available achiral substrates. This convergent approach can find an application in fragment-based drug discovery process.

Abstract A convergent approach to highly functionalized 3‐hydroxyisoquinolines is reported. The key steps are an Ugi multicomponent reaction and a subsequent intramolecular reductive Heck reaction; these can also be performed as one‐pot procedure. structures display very interesting properties blue‐fluorescence emitters. Photophysical studies on the absorption static fluorescence indicate that substitution pattern pyridyl part influences optical only minor extent, unless amide substituent...

Abstract A tandem Ugi/Mitsunobu protocol, starting from o ‐aminophenols, α‐hydroxy acids, amines and aldehydes gives benzo[ b ][1,4]oxazin‐3‐ones of general formula 1 in two high‐yielding steps, with the introduction up to four diversity inputs. The mildness methodology allows stereospecific synthesis enantiomerically pure products as well additional functional groups. overall procedure can also be carried out a one‐pot manner.

α-Azido aldehydes can be employed in Passerini reactions with isocyanides and various propiolic acids to afford the three-component adducts moderate good yields. These compounds undergo a straightforward azide-alkyne dipolar cycloaddition furnish triazolo-fused dihydrooxazinones.

Abstract To access enantiopure multicomponent reaction (MCR) products, the two most convenient approaches are (1) development of an asymmetric catalytic version MCR, starting from achiral substrates; and (2) use chiral, enantiomerically pure inputs by taking advantage substrate‐controlled diastereoselection achieved during MCR step. In this microreview we will focus on second alternative strategy and, more specifically, generation chiral through biocatalytic or organocatalytic methodologies.

Multicomponent reactions are often recognized for their efficiency and convergency, if compared with multistep organic synthesis. Nevertheless, we here demonstrate that a four-step-one-pot approach (named OPHA strategy the initials of four steps involved) is not only able to afford compounds could be obtained by an alkylative Passerini reaction but also capable generating them minimal loss atoms high operational simplicity, as in typical multicomponent approach.

The reaction of isocyanomethylenetriphenylphosphorane, generated in situ from the corresponding phosphonium salt, with a diverse set aldehydes afforded vinyl isocyanides good to high yields. Excellent E-selectivity was observed for aliphatic and 2,6-disubstituted aromatic aldehydes, whereas Z-olefins were formed predominantly ortho-substituted aryl aldehydes. (Z)-1-Bromo-2-(2-isocyanovinyl)benzene (5l) found be truly universal isonitrile since, after Ugi reaction, resulting secondary amide...

Lewis acid catalyzed Passerini reactions on chiral aldehydes derived from desymmetrized erythritol take place with unprecedented diastereoselectivity. The resulting adducts have been selectively and efficiently converted into a variety of densely functionalized, polyoxygenated heterocycles.