Condensation of Dimethyl Acetylenedicarboxylate with Malononitrile, Ethyl Cyanoacetate, and Malonate Esters

The preparation of several 1,2,3,4,5-functionalized cyclopentane derivatives

“…The first route dates back to studies by Diels, Alder and co-workers [11–12], carried out in the early 1930s and 40s, which were taken up later by Le Goff and his students [13]. These pioneers demonstrated that, on treatment of dimethyl acetylenedicarboxylate ( 22 ) with dimethyl malonate ( 23 ) under the catalytic influence of pyridinium acetate, the fully substituted cycloheptadienes 24 and 25 (Scheme 5) were produced; both authors also proposed reaction mechanisms for this complex transformation that can be considered as reasonable even today; for the details the reader is referred to the original literature [12–13].…”

“…Preparation of the cycloheptadiene octaesters 24 / 25 according to Diels [11] and Le Goff [13], respectively, followed by ring contraction to the cyclopentadiene pentaester 28 .…”

Synthesis and characterization of chromium(I) bis(η6-toluene) derivatives containing sterically demanding anions

“…We adopted the BP86 scheme, that uses the functional proposed by Becke [38] and Perdew [39], and the 6-31G** basis set that is appropriate for calculations of split-valence-plus-polarization quality. The following compounds were prepared as reported in the literature: Cr(g 6 -MeC 6 H 5 ) 2 [40], pcmcpH [41], dbcpH [11].…”

Reactivity of bis(η6-arene) derivatives of titanium, vanadium and niobium with fulvenes bearing electron-withdrawing substituents

“…EPR spectra were simulated using the WINSIM 32 program [30]. The following compounds were prepared as reported in the literature: Ti(g 6 -MeC 6 H 5 ) 2 [31], V(g 6 -1,3,5-Me 3 C 6 H 3 ) 2 [32], Nb(g 6 -1,3,5-Me 3 C 6 H 3 ) 2 [33], NbCl 3 (DME) 1.4 [34], ''pentacarbomethoxycyclopentadiene'' [35], K[pcmcp] [3], 1-benzoyl-6-hydroxy-6-phenyl fulvene [4a], and 1-benzoyl-3-nitro-6-hydroxy-6-phenyl fulvene [4b].…”