1498-79-9Relevant articles and documents
Heteroleptic Ni(II) Complexes Bearing a Bulky Yet Flexible IBiox-6 Ligand: Improved Selectivity in Cross-Electrophile Coupling of Benzyl Chlorides with Aryl Chlorides/Fluorides
Shen, Zheng-Wang,Meng, Die-Die,Imran, Sajid,Yan, Chun-Hui,Sun, Hong-Mei
supporting information, p. 3540 - 3545 (2020/10/09)
A bisoxazoline-derived NHC known as IBiox-6 reacted smoothly with Ni[P(OEt)3]2Br2 and Ni(PPh3)2Br2 to give the respective heteroleptic Ni(II) complexes Ni(IBiox-6)[P(OEt)3]Br2 (1) and Ni(IBiox-6)(PPh3)Br2 (2) in yields of 60% and 71%. Their crystal structures were characterized to reveal a rare cis disposition of the IBiox-6 ligand to the phosphite ligand in 1, while 2 possessed the more common trans configuration. Both complexes catalyzed the cross-electrophile coupling of benzyl chlorides with aryl chlorides and fluorides in the presence of Mg turnings at 50 °C via a "real one-pot"procedure, featuring no requirement for temperature variation or portionwise addition of any coupling partner. In particular, complex 1 showed a better balance between the catalytic activity and selectivity. The scope of the procedure catalyzed by 1 and Mg turnings was investigated, providing a highly selective, simple, and practical approach to the synthesis of diarylmethanes with high steric hindrance and various functional groups, including oligo-diarylmethane with asymmetric structures.
Protonation and Alkylation of Ambident (9-Anthryl)arylmethyl Anions
Takagi, Masato,NOjima, Masamoto,Kusabayashi, Shigekazu
, p. 4676 - 4684 (2007/10/02)
We have investigated the protonation of ambident (9-anthryl)arylmethylsodiums (Na-2) and -lithiums (Li-2) (substituent =p-Me, p-Me, H, m-F) with various oxygen and carbon acids in tetrahydrofuran to give a mixture of the anthracene derivatives 3a-d and the 9,10-dihydroanthracenes 4a-d.Product compositions were dramatically influenced by the substituent electronic effects of the carbanions 2 and the acidities of the proton donors.In the protonation with the oxygen proton donors the change of the countercation 2 and the addition of hexamethylphosphoramide also exerted remarkable effects on the 3:4 ratio, whereas these two factors were not important in the case of the carbon acids.This fact would be interpreted as the extent of coordination of oxygen acids to metal cations being important in determining protonation regiochemistry.The reaction of (9-anthryl)arylmethyl anions (2a-d) with a series of aliphatic and benzylic halides gave a mixture of two cross-coupling products, 7 (coupling at C-α) and 8 (coupling at C-10), and/or dimers, 5 Cα-C10 coupling) and 6 (C10-C10 coupling), the composition being influenced by the substituent electronic effects of the carbanions 2 and structure of the alkyl groups of the halides.The leaving group effects also have a significant influence on the product composition.Using dependence (or independence) of the product composition on the electronic effects of the substituent of 2 as a tool to differentiate the reaction mechanisms, we have attempted to rationalize the apparently complicated alkylation of the carbanions 2.
Reactions of (9-Anthryl)arylmethyl Chloride and Its Homologues with Nucleophiles under Solvolytic Conditions. Notable Effects of Reaction Conditions and Substituents on the Reaction Sites
Ogata, Fujimaro,Takagi, Masato,Nojima, Masatomo,Kusabayashi, Shigekazu
, p. 1145 - 1153 (2007/10/02)
The reactions of (9-anthryl)arylmethyl chlorides 2a-e (the substituents are p-MeO, p-Me, H, p-Cl, and m-Cl), the corresponding bromides 3b-d (the substituents are p-Me, H, and p-Cl), and the antimonate salts 4b-e (the substituents are p-Me, H, p-Cl, and m
