756484-28-3Relevant academic research and scientific papers
Synthesis of Functionalized Phenanthrenes via Regioselective Oxidative Radical Cyclization
Pati, Kamalkishore,Michas, Christopher,Allenger, David,Piskun, Ilya,Coutros, Peter S.,Dos Passos Gomes, Gabriel,Alabugin, Igor V.
, p. 11706 - 11717 (2015)
The majority of Sn-mediated cyclizations are reductive and, thus, cannot give a fully conjugated product. This is a limitation in the application of Sn-mediated radical cascades for the preparation of fully conjugated molecules. In this work, we report an oxidatively terminated Bu3Sn-mediated cyclization of an alkyne where AIBN, the commonly used initiator, takes on a new function as an oxidative agent. Sn-mediated radical transformation of biphenyl aryl acetylenes into functionalized phenanthrenyl stannanes can be initiated via two potentially equilibrating vinyl radicals, one of which can be trapped by the fast 6-endoclosure at the biphenyl moiety in good to excellent yields. The efficient preparation of Sn-substituted phenanthrenes opens access to convenient building blocks for the construction of larger polyaromatics.
Invisible Chelating Effect Exhibited between Carbodicarbene and Phosphine through π-π Interaction and Implication in the Cross-Coupling Reaction
Shih, Wei-Chih,Chiang, Yun-Ting,Wang, Qing,Wu, Ming-Chun,Yap, Glenn P. A.,Zhao, Lili,Ong, Tiow-Gan
supporting information, p. 4287 - 4297 (2017/11/20)
Palladium complexes supported with the mixed ligands carbodicarbene (CDC) and different phosphine ligands (PPh3, PTol3, and PCy3) were prepared, and their molecular structures were characterized. Examination of the structures of 2-PPh3 and 2-PTol3 with cis configuration discloses the existence of an unexpected π-π interaction between one phenyl group of the phosphine and the benzimidazole ring of a CDC. The palladium complex 2-PPh3 is an active Suzuki-Miyaura catalyst with a wide scope of substrates containing various functional groups and steric demands. In contrast to electron-withdrawing aryl bromide, the yield of product for electron-rich substrates was improved by adding a catalytic amount of DMSO under aerobic conditions. The solution NMR and structural analysis has revealed that the intramolecular π-π interaction between CDC and phosphine ligands has a positive influence on the activity of the reaction, which is further supported by quantum chemical calculations.
Phenanthrene synthesis by eosin Y-catalyzed, visible light- Induced [4+2] benzannulation of biaryldiazonium salts with alkynes
Xiao, Tiebo,Dong, Xichang,Tang, Yanchi,Zhou, Lei
supporting information, p. 3195 - 3199 (2013/01/16)
A metal-free, visible light-induced [4+2] benzannulation of biaryldiazonium salts with alkynes was developed. With eosin Y as photoredox catalyst, a variety of 9-substituted or 9,10-disubstituted phenanthrenes were obtained via a cascade radical addition and cyclization sequence. Copyright
