Entity

Time filter

Source Type


Huang S.,Fudan University | Shao Y.,Fudan University | Zhang L.,Fudan University | Zhou X.,Fudan University | Zhou X.,State Key Laboratory of Organometallic Chemistry
Angewandte Chemie - International Edition | Year: 2015

The first catalytic cycloamidination of aminoalkenes with nitriles has been achieved by using rare-earth complexes. This reaction is equivalent to the desired intramolecular hydroamination of alkenylamidines, and allows a new direct access to substituted 2-imidazolines and tetrahydropyrimidines in high yields under operationally simple reaction conditions. Moreover, the methodology is also efficient for synthesis of symmetric and unsymmetric bridged diimidazolines. Compared with the traditional stepwise-mediated synthetic approaches, the present method avoids the use of additives and harsh reaction conditions, and thus leads to a completely different product distribution. Mechanistic data suggest that the reaction involves the initial NH activation by lanthanide complex followed by nitrile insertion into a Ln-N bond to form an amidinate lanthanide intermediate which undergoes the cyclization. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yi W.,Fudan University | Zhang J.,Fudan University | Chen Z.,Fudan University | Zhou X.,Fudan University | Zhou X.,State Key Laboratory of Organometallic Chemistry
Organometallics | Year: 2012

The mixed Tp Me2/Cp-supported yttrium monoalkyl (Tp Me2)CpYCH 2Ph(THF) (1) reacted with 1 equiv of PhCN in THF at room temperature to afford the imine-enamine tautomer (Tp Me2) CpY(N(H)C(Ph)=CHPh)(THF) (2) and the insertion product (Tp Me2)CpY(N= C(CH 2Ph)Ph)(THF) (3), in 61% and 12% isolated yields, respectively. 2 further reacted with PhCN in toluene at 120 °C to give the N-H bond addition product (Tp Me2)CpY(N(H)C(Ph)NC(Ph)=CHPh) (4). Treatment of 1 with 1 equiv of anthranilonitrile produced the dimer [(Tp Me2) CpY(μ-NHC 6H 4CN)] 2 (5). The monomer product (Tp Me2)CpY(NHC 6H 4CN)(HMPA) (6) can be obtained through the coordination of HMPA (hexamethylphosphoric triamide). The reaction of 5 with 1 in THF at room temperature gave the cyano group insertion product [(Tp Me2)CpY(THF)] 2(μ-NHC 6H 4C(CH 2Ph)=N) (7). However, this reaction under the heating conditions gave an unexpected rearrangement product, (Tp Me2)CpY(THF) (η 2-NHC 6H 4C(CH 2Ph)=NH) (8). 5 further reacted with o-aminobenzonitrile at 120 °C to afford the nucleophilic addition/cyclization product Tp Me2Y[κ 3- (4-NH=(C 8N 2H 4)(2-NHC 6H 4)](HMPA) (9), accompanied with the elimination of the Cp ring. These results indicated that the yttrium alkyl complex exhibits high activity toward organic nitriles and reveals some unusual transformations during the insertion process. All these new complexes were characterized by elemental analysis and spectroscopic methods, and their solid-state structures were also confirmed by single-crystal X-ray diffraction analysis. © 2012 American Chemical Society.


Liu R.,Fudan University | Zhou X.,Fudan University | Zhou X.,State Key Laboratory of Organometallic Chemistry
Chemical Communications | Year: 2013

Cyclopentadienyl and substituted cyclopentadienyl ligands are observed in a wide range of organometallic complexes. In addition to serving as ancillary ligands, these ligands have come into their own as intermediates in organometallic reactions, and shown many unique reaction modes involving ring C-H, C-C and CC bond cleavages. This feature article summarizes the progressive development of cyclopentadienyl-based reactions of metallocene complexes of transition metals and rare-earth metals, with the aim of further developing the fundamental modes of reactivity of such systems together with their synthetic applications. © 2013 The Royal Society of Chemistry.


Hong L.,Fudan University | Shao Y.,Fudan University | Zhang L.,Fudan University | Zhou X.,Fudan University | Zhou X.,State Key Laboratory of Organometallic Chemistry
Chemistry - A European Journal | Year: 2014

A lanthanide-catalyzed sequential insertion of C≡N and C≡C into an N-H bond is presented. The convenient reaction, which proceeds under mild conditions, is an efficient method for preparing 1,2,4-trisubstituted imidazoles directly from readily available propargylamines and nitriles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li Z.,Fudan University | Hong J.,Fudan University | Zhou X.,Fudan University | Zhou X.,State Key Laboratory of Organometallic Chemistry
Tetrahedron | Year: 2011

A highly efficient and environmentally friendly method for catalytic chalcogenylation of imidazopyridines, imidazopyrimidines, indoles, and pyrrolo[2,3-b]pyridines with dichalcogenides has been developed by using CuI as catalyst under air. The reactions proceed smoothly to give the desired products in moderate to excellent yields, without the presence of other additive. © 2011 Elsevier Ltd. All rights reserved.

Discover hidden collaborations