A Cope Rearrangement in the Reaction Catalyzed by Dimethylallyltryptophan Synthase?

2011 ◽  
Vol 133 (32) ◽  
pp. 12342-12345 ◽  
Author(s):  
Louis Y. P. Luk ◽  
Qi Qian ◽  
Martin E. Tanner
Keyword(s):  
Cope Rearrangement ◽  
Dimethylallyltryptophan Synthase

Rearrangements in the mechanisms of the indole alkaloid prenyltransferases

2013 ◽  
Vol 85 (10) ◽  
pp. 1935-1948 ◽  
Author(s):  
Niusha Mahmoodi ◽  
Qi Qian ◽  
Louis Y. P. Luk ◽  
Martin E. Tanner
Keyword(s):  
Indole Alkaloid ◽  
Ion Pair ◽  
Pair Formation ◽  
Tryptophan Residue ◽  
Cope Rearrangement ◽  
Indole Ring ◽  
Structural Homology ◽  
Dimethylallyl Diphosphate ◽  
Free Tryptophan ◽  
Dimethylallyltryptophan Synthase

The indole prenyltransferases are a family of metal-independent enzymes that catalyze the transfer of a prenyl group from dimethylallyl diphosphate (DMAPP) onto the indole ring of a tryptophan residue. These enzymes are remarkable in their ability to direct the prenyl group in either a “normal” or “reverse” fashion to positions with markedly different nucleophilicity. The enzyme 4-dimethylallyltryptophan synthase (4-DMATS) prenylates the non-nucleophilic C-4 position of the indole ring in free tryptophan. Evidence is presented in support of a mechanism that involves initial ion pair formation followed by a reverse prenylation at the nucleophilic C-3 position. A Cope rearrangement then generates the C-4 normal prenylated intermediate and deprotonation rearomatizes the indole ring. The enzyme tryprostatin B synthase (FtmPT1) catalyzes the normal C-2 prenylation of the indole ring in brevianamide F (cyclo-L-Trp-L-Pro). It shares high structural homology with 4-DMATS, and evidence is presented in favor of an initial C-3 prenylation (either normal or reverse) followed by carbocation rearrangements to give product. The concept of a common intermediate that partitions to different products via rearrangements can help to explain how these evolutionarily related enzymes can prenylate different positions on the indole ring.

scholarly journals Stereoselective Tandem Iridium-Catalyzed Alkene Isomerization-Cope Rearrangement of ω-diene Epoxides: Efficient Access to Acyclic 1,6-Dicarbonyl Compounds

2021 ◽  
Author(s):  
Rahul Suresh ◽  
Itai Massad ◽  
Ilan Marek
Keyword(s):  
Bond Cleavage ◽  
Cope Rearrangement ◽  
Dicarbonyl Compounds ◽  
Alkene Isomerization ◽  
Efficient Access

The Cope rearrangement of 2,3-divinyloxiranes, a rare example of epoxide C-C bond cleavage, results in 4,5-dihydrooxepines which are amenable to hydrolysis, furnishing 1,6-dicarbonyl compounds containing two contiguous stereocenters at the 3- and 4- positions. We employ...

Cope rearrangement of 9-methylenebarbaralane. Complete line shape analysis

1973 ◽  
Vol 38 (6) ◽  
pp. 1210-1215 ◽  
Author(s):  
Linda G. Greifenstein ◽  
Joseph B. Lambert ◽  
Michael J. Broadhurst ◽  
Leo A. Paquette
Keyword(s):  
Shape Analysis ◽  
Line Shape ◽  
Cope Rearrangement ◽  
Line Shape Analysis

A Versatile Hexadiene Synthesis by Decarboxylative sp3—sp3 Coupling/Cope Rearrangement.

ChemInform ◽  
2006 ◽  
Vol 37 (48) ◽  
Author(s):  
Shelli R. Waetzig ◽  
Dinesh K. Rayabarapu ◽  
Jimmie D. Weaver ◽  
Jon A. Tunge
Keyword(s):  
Cope Rearrangement
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