Cyclization cascade reactions

Balme G, Bouyssi D, Monteiro N (2006) The Virtue of Michael-Type Addition Processes in the Design of Transition Metal-Promoted Cyclizative Cascade Reactions. 19 115-148 Barluenga J, Rodriguez F, Fanands FJ, Fldrez J (2004) Cycloaddition Reaction of Group 6 Fischer Carbene Complexes. 23 59-121 Basset J-M, see Candy J-P (2005) 16 151-210... 

Keywords ninhydrin, dimedone, aminocrotonate,, cyclization, cascade reaction, waste-free, solid-solid reaction... 

Keywords acetone, o-phcnylcndiaminc, cyclization, cascade reaction, gas-solid reaction, benzodiazepine, benzothiazolidine... 

Keywords o-phenylendiamine, parabanic acid, cyclization, cascade reaction, melt reaction, quinoxaline... 

The Virtue of Michael-Type Addition Processes in the Design of Transition Metal-Promoted Cyclizative Cascade Reactions... 

Intermolecular Addition-Indole Cyclization Cascade Reactions... 

Kopecky, D. J., Rychnovsky, S. D. Mukaiyama Aldol-Prins Cyclization Cascade Reaction A Eormal Total Synthesis of Leucascandrolide A. J. Am. Chem. Soc. 2001, 123, 8420-8421. 

The synthesis was started from 4-aminobutanol 10, which on treatment with A-Boc-protected 5-methylisothiourea 11 followed by oxidation under Swem condition yielded aldehyde 12. 2,4-Dimethoxybenzyl amine 13 was treated with aldehyde 12 to make imine and then it was treated with acyl chloride 14 to perform acylation /cyclization cascade reaction to make protected synoxazolidinone B scaffold 15, which on global deprotection yielded synoxazolldinone B (2) with reasonably good overall yield (20% in four steps) [14],... 

Most AFC alkylation reactions are focused on relatively reactive furans, pyrroles, and indoles, whereas benzene derivatives are much less explored. The Wang group reported the organocatalytic asymmetric synthesis of chromane and dihydrobenzopyrane derivatives 121 from readily available 1-naphthols and a,p-unsaturated aldehydes by the AFC alkylation/cyclization cascade reaction (Scheme 6.49). The process appeared to have a broad substrate... 

Scheme 6.49 Organocatalytic AFC alkylation/cyclization cascade reaction of 1-naphthols with o,p-unsaturated aldehydes reported by Wang.

Optically active trifluoromethyl-substituted tetrahydroimidazo[l, 5-c] quinazoline derivatives 44 were synthesized by Zhao and coworkers via a diastereo- and enantioselective Mannich-type cyclization cascade reaction of a-aryl isocyanoacetates and trifluoromethyl-substituted cyclic ketimines, using a multihydrogen-bonding donor squaramide/AgOAc cooperative catalytic system in THF at 0°C (Scheme 30) (140L4566). The products were obtained in 76—99% yield with a diastereomeric ratio of greater than 15 1 and 58-98% enantiomeric excess. 

Progress in asymmetric organocatalyzed Michael addition/hemi-amino-acetalization/acylimminium-cyclization cascade reactions and application of this type of reactions in the synthesis of alkaloids 13CJ01. Progress in synthesis of benzophenanthridine alkaloids and their derivatives 12CJO1605. 

Scheme 35 Vinylogous Michael addition-cyclization cascade reaction to form spiro-oxindoles...

HongL, WangL, Sun WS, Wong KY, Wang R (2009) Organocatalytic AsymmetricEnede/-Crafts AUcylation/Cyclization Cascade Reaction of 1-Naphthols and a,P-Unsaturated Aldehydes An Enantioselective Synthesis of Chromanes and Dihydrobenzopyranes. J Org Chem 74 6881... 

Saito and Hanzawa extended their cydoisomerization route, involving the amino-Claisen rearrangement-cyclization cascade reaction (Scheme 9.68), to a one-pot procedure toward the functionalized 2,3-dimethylindole derivatives 281 (Scheme 9.97) [226]. The key propargyl anilines 280 were generated in situ via the propargylation of substituted anilines 278 with the propargrl bromide 279. 

---