Regioselective Synthesis of Tetraphenyl-1,3-butadienes with Aggregation-Induced Emission
摘要:
In the presence of substoichiometric amounts of Co2(CO)8, internal bisarylalkynes undergo reductive dimerization with good to excellent yields. The Co2(CO)(8)-induced reactions described are experimentally quite simple and provide a very useful synthetic procedure for the synthesis of tetraphenylbutadienes which exhibit aggregation-induced emission enhancement, i.e., weak emission in good solvents but strong fluorescence in solvents that lead toward formation of aggregates or in the solid state.
Construction of Halofunctionalized Indenes via a Cascade Prins‐Nazarov Cyclization Promoted by Dual Roles of BX
<sub>3</sub>
作者:Sabera Sultana、Yong Rok Lee
DOI:10.1002/adsc.201901266
日期:2020.2.21
carboxaldehydes and borontrihalides (BX3, X=F, Cl, Br, I) is described. A diverse array of halofunctionalized indenes substituted with a heterocycle has been synthesized regioselectively with BX3 as a promotor for the carbocyclization and a source of X− for halogenation. This reaction proceeds via a formal halogenative [4+1] cycloaddition between arylalkynes and carboxaldehydes promoted by borontrihalides to generate
An efficient Pd(OAc)(2)/Cu(Xantphos)I system for Sonogashira coupling is disclosed. Aryl bromides/iodides and electron-poor aryl chlorides were suitable for this reaction. The experimental results suggest that Cu (Xantphos)I plays a unique role in which the phosphine ligand coordinates with copper. (C) 2016 Elsevier Ltd. All rights reserved.