12129-27-0Relevant articles and documents
Comparison of the Reactivity of Paracyclophane and p-Xylene
Dyson, Paul J.,Humphrey, David G.,McGrady, John E.,Mingos, D. Michael P.,Wilson, D. James
, p. 4039 - 4044 (1995)
The relative abilities of paracyclophane (C16H16) and p-xylene (C6H4Me2-1,4) to form arene tricarbonyl complexes from chromium hexacarbonyl has been studied in dioxane using the Strohmeier reflux method, and the rate constants contrasted.The reactions are found to proceed more quickly with paracyclophane by ca. 25percent.Density functional molecular-orbital calculations have rationalised this observation, and indicate that the enhanced reactivity of the paracyclophane system relative to p-xylene is a consequence of repulsive interactions between the two arene decks in the former, which are relieved to some extent by co-ordination of the electron-withdrawing Cr(CO)3 fragment.
Chromium carbonyl complexes with aryl mono- and oligogermanes: Ability for haptotropic rearrangement
Zaitsev, Kirill V.,Gloriozov, Igor P.,Oprunenko, Yuri F.,Lermontova, Elmira Kh,Churakov, Andrei V.
, p. 217 - 227 (2019)
The intra- and intermolecular inter-ring η6 ? η6-haptotropic rearrangements (IRHR), occurring by involving interactions to Ge atoms in arylgermanes, were investigated theoretically and experimentally. The new methods for the synthesis of non-symmetrical polyaromatic Ge compounds were elaborated. Digermane Ph3GeGeMe2Cl (2) was obtained from Ph3GeGeMe2NMe2 (1) under action of Me3SiCl. Aryl digermane Ph3GeGeMe2(η6-C6H5)Cr(CO)3 (4) was obtained after lithiation of (η6-C6H6)Cr(CO)3 (3) with subsequent interaction with 2. It was established that thermally induced intramolecular IRHR in 4 is not observed experimentally; at similar reaction conditions in the presence of tetralin C10H12 (7) the bimolecular intermolecular IRHR occurs giving (η6-C10H12)Cr(CO)3 (8). DFT analysis of the intramolecular IRHRs for model germane (p-Tol)2Ge(H)(η6-Tol-p)Cr(CO)3 (MC1) and digermane Ph3GeGeH2(η6-C6H5)Cr(CO)3 (MC2) indicates a plausible effect of 3c-2e (agostic) Ge–H···Cr interaction on success of such rearrangement. The theoretical activation barrier is determined to be in the range of 35–37 kcal/mol. The model compound (η6-C6H3(GeHPh2)Me2-p)Cr(CO)3 (12) was obtained from (η6-C6H4Me2-p)Cr(CO)3 (11). The decomposition of 12 was observed under conditions of thermally induced IRHR. Molecular structures of 8, 11 and 12 in a crystal were investigated by XRD.
Benzylic functionalization of (η6-alkylarene)chromium tricarbonyl complexes
Kalinin, Valery N.,Cherepanov, Il'ya A.,Moiseev, Sergey K.
, p. 437 - 455 (2007/10/03)
A general method for the regioselective benzylic metallation of (η6-alkylarene)chromium tricarbonyl complexes on the action of lithium amides in THF under very mild conditions has been developed. Transmetallation reactions of the lithium derivatives thus obtained produce the corresponding benzylic organotin, zinc and copper chromium tricarbonyl complexes. Methods for the preparative benzylic functionalization of (η6-alkylarene)chromium tricarbonyl complexes have been developed, including carboxylation, α-hydroxyalkylation, γ-carbonylation, acylation, arylation, vinylation, heteroarylation and alkylation procedures. 5-Acetoxy-3-benzyl-1,4-methano-2,3,4,5-tetrahydro-1H-3-benzazepine has been prepared using the benzylic lithium derivative of the (η6-alkylarene)chromium tricarbonyl complex at the key step. This compound is a representative of the major class of physiologically active compounds known as C-norbenzomorphans.
