105970-96-5Relevant academic research and scientific papers
An Anionic 3 + 2 Cyclization-Elimination Route to Cyclopentenes
Beak, Peter,Burg, Duglas A.
, p. 1647 - 1654 (2007/10/02)
The formation and reactions of lithium (10) are reported.When 10 is allowed to react with olefins bearing an electron-withdrawing group the 4-substituted cyclopent-1-enecarboxamides 11-19 are produced in 22-89percent yields.Methyl-substituted analogues of 10, the allyllithium reagents 23 and 25, react in a similar manner to produce cyclopentenes that have methyl groups in the 2 or 5 positions.The corresponding lithium and lithium reagents also react with electron-deficient olefins to produce the substituted cyclopentenes 28 and 30, which can be hydrolyzed readily to the carboxylic acid 42.The formation of the cyclopentenes occurs in a stepwise fashion by an initial highly regioselective addition to the electron-deficient olefin by the allyllithium reagent followed by a 5-Endo-Trig cyclization and elimination of benzenesulfinate.The allyllithium 10 undergoes polydeuteration on reaction with methanol-O-d and acetone-d6, alkylation with methyl iodide, and addition-dehydratation on reaction with benzaldehyde.
[1-(Phenylthio)-2-carbamoylallyl]lithium reagents. Electrophilic substitution and formal anionic 3 + 2 cyclization-elimination
Beak, Peter,Wilson, Kenneth D.
, p. 218 - 225 (2007/10/02)
The formation and reaction of a number of [1-(phenylthio)-2-carbamoylallyl]lithium reagents is reported. Lithiation of the β′- and β-(phenylthio)-α,β-unsaturated carbamates provides 8, 13, and 35 from tertiary amides and 26, 32, and 45 from secondary amides. These reagents are geometrically stable and react regioselectively with a variety of electrophiles. The reaction of 8 with N-methyl-N-phenylacrylamide gives the cyclopentenes 42 and 43 while reactions of 13 and 45 with azobenzene gives the dihydropyrazoles 44 and 46, respectively. These sequences involve β′-directed lithiations, stepwise anionic 3 + 2 cyclizations, and thermodynamically driven eliminations. The formation of the quinoline 47 from 12, an adduct of 8 and azobenzene, is reported.
AN ANIONIC 3+2 CYCLIZATION-ELIMINATION ROUTE TO CYCLOPENTENES
Beak, Peter,Burg, Douglas A.
, p. 5911 - 5914 (2007/10/02)
Anionic 3+2 cyclization-elimination reactions between 1-benzenesulfonyl-2-(N,N-diisopropyl)carboxamidoallyllithium (2) and electron-deficient olefins provide the 4-substituted-N,N-diisopropylcyclopent-1-ene carboxamides 3-8 in yields of 22-89percent.
