32825-32-4Relevant academic research and scientific papers
Structures, dynamic behaviour in solution and cross-coupling reactions of the α-palladiated (η6-alkylarene)tricarbonylchromium complexes containing a palladium-chromium bond
Moiseev,Cherepanov,Petrovskii,Ezernitskaya,Butenscho?n,Strotmann,Kalinin
, p. 71 - 74 (1998)
Structures of the complexes (η3-C3H5)Pd(μ-ηn 6:1-CH2Ph)Cr(CO)3 and (η3-C3H5)Pd[μ-η 6:1-CH(Ph)Ph]Cr(CO)3 in solution were evaluated by NMR (1H and 13C) and IR spectroscopy. The dynamic behaviour of the complexes was investigated. Quick rotation (on the NMR time scale) of the tricarbonylchromium groups around the axis passing through the centre of the η6-coordinated phenyl ring and the chromium atom takes place at room temperature and becomes slow on cooling. The η3-allylic ligand was proved to undergo no dynamic changes in solution. Unlike the solid state, the semi-bridging carbonyl groups between chromium and palladium atoms are absent or very weak in solution. Cross-coupling reactions of the complexes with organohalides are described.
Palladium-catalyzed allylic substitution with (η6-Arene- CH2Z)Cr(CO)3-based nucleophiles
Zhang, Jiadi,Stanciu, Corneliu,Wang, Beibei,Hussain, Mahmud M.,Da, Chao-Shan,Carroll, Patrick J.,Dreher, Spencer D.,Walsh, Patrick J.
, p. 20552 - 20560 (2012/02/13)
Although the palladium-catalyzed Tsuji-Trost allylic substitution reaction has been intensively studied, there is a lack of general methods to employ simple benzylic nucleophiles. Such a method would facilitate access to "α-2-propenyl benzyl" motifs, which are common structural motifs in bioactive compounds and natural products. We report herein the palladium-catalyzed allylation reaction of toluene-derived pronucleophiles activated by tricarbonylchromium. A variety of cyclic and acyclic allylic electrophiles can be employed with in situ generated (η6-C 6H5CHLiR)Cr(CO)3 nucleophiles. Catalyst identification was performed by high throughput experimentation (HTE) and led to the Xantphos/palladium hit, which proved to be a general catalyst for this class of reactions. In addition to η6-toluene complexes, benzyl amine and ether derivatives (η6-C6H5CH 2Z)Cr(CO)3 (Z = NR2, OR) are also viable pronucleophiles, allowing C-C bond-formation α to heteroatoms with excellent yields. Finally, a tandem allylic substitution/demetalation procedure is described that affords the corresponding metal-free allylic substitution products. This method will be a valuable complement to the existing arsenal of nucleophiles with applications in allylic substitution reactions.
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.
X-ray structural study of the first bicluster ?-arene complex 6-PhCo4(CO)9>2CH2 and binuclear complex 6-PhCr(CO)3>2CH2
Yanovsky, A. I.,Dolgushin, F. M.,Struchkov, Yu. T.,Kaganovich, V. S.,Rybinskaya, M. I.
, p. 1072 - 1079 (2007/10/02)
In has been established by X-ray structural study that the bucluster cobalt ?-arene complex of diphenylmethane 6-PhCo4(CO)9>2CH2 and binuclear complex 6-PhCr(CO)3>2CH2 have an s-trans-s-trans conformation in their crystals. - Key
Mono-, bi- and polynuclear complexes of diphenylmethane with Cr, Co and Ru. Synthesis and investigation by 1H, 13C and 17O NMR
Kolehmainen, E.,Laihia, K.,Korvola, J.,Kaganovich, V.S.,Rybinskaya, M.I.,Kerzina, Z.A.
, p. 109 - 114 (2007/10/02)
Complexes of diphenylmethane (Ph2CH2):Ph2CH2Cr(CO)3 (1), Ph2CH22 (2), Ph2CH2Co4(CO)9 (3), Ph2CH22 (4), Ph2CH2Cr(CO)3Co4(CO)9 (5) and Ph2CH2Ru6C(CO)14 (6) have been prepared and characterized by 1H and 13C- and 17O-NMR spectroscopy.Stron
Electrophilic Substitution in (Arene)tricarbonylchromium Complexes. Part 1.
von Rosenberg, Joseph L.,Pinder, A. Reginald
, p. 747 - 752 (2007/10/02)
The Friedel-Crafts acetylation of several (arene)tricarbonylchromium complexes have been investigated.From the results it is concluded that the tricarbonylchromium group deactivates to a small extent towards electrophilic substitution the ring to which it is attached.In the case of tricarbonyl(diphenylmethane)chromium (1; n=1), however, attack occurred on both rings to about an equal extent, possible explanations for this unexpected behaviour are advanced.
