Catalytic tandem

This catalytic tandem carbene addition-bicyclization of enynes has been very recently applied to the synthesis of fluorinated bicyclo[ .0.l]-amino esters.176... 

A catalytic tandem conjugate addition-aldol cyclization950 allowed the formation of five- and six-membered ring products from aromatic and aliphatic ketone precursors (Equation (218)).974... 

A catalytic tandem cyclopropanation-ring-closing metathesis of dienyne 80 led to derivative 81 in good yield (Scheme 30 <2004JA9524>). For internal alkynes, carbene-mediated ring-closing enyne metathesis was observed. Less favorable alkyne binding leads to preferential reactions of the metal carbene with the 1-alkene moiety. 

Catalytic tandem isomerization/Claisen reaction of bis allyl ether was reported by Dixneuf et al. [23]. A cationic bis-oxazoline-ruthenium-arene complex S3 in the presence of both l,3-bis(2,6-diisopylphenyl)imidazolinium chloride and CS2CO3 catalyzes the selective transformation of bis-allyl ether 51 into ) c5-unsaturated aldehyde 52 via successive alkene isomerization and Claisen rearrangement (Eq. 12.21). 

Synthesis of p-lactams by transition metal promoted Staudinger reactions Alternative synthetic approaches from transition metal enhanced organocatalysis to in situ, highly reactive intermediate synthesis and catalytic tandem reactions 130BC5976. 

Scheme 13.12 Catalytic tandem double 1,3-dipolar cycloaddition of 1,4-benzoquinone 53.

For some years the group of Li Deng has been investigating carefully the use of Cinchona alkaloids in asymmetric organocatalysis resulting in the development of numerous highly useful applications 424). Recently, they developed a catalytic tandem conjugate addition/protonation protocol to access compounds with tertiary... 

The boron enolates (up to 98% ee) were used for further transformation by treatment with electrophiles. The rhodium-catalyzed reaction of B-Ph-9BBN was extended to a new type of catalytic tandem conjugate addition-aldol reaction by combination with vinyl ketones and aldehydes [39]. 

Guo, S., Xie, Y, Hu, X., Xia, C., Huang, H. (2010). Diastereo- and enantioselective catalytic tandem Michael addition/Mannich reaction Access to chiral isoindohnones and azetidines with multiple stereocenters. Angewandte Chemie International Edition, 49, 2728-2731. 

An efficient total synthesis of bruguierol A was accomplished from commercially available (S)-epichlorydrin (Scheme 18.57) [47]. The key step is a catalytic tandem intramolecular hydroalkoxylation/hydroarylation reaction to construct a 2,3-benzofused 8-oxobicyclo[3.2.1]octane system. Bruguierol A belongs to a family of compounds termed bruguierol A to C, isolated from the stem of the Bruguiera gym-morrhiza tree. 

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