physical properties mainly depend on their structures, the precise synthesis of structurally well-defined GNRs is highly desirable to control their properties. Herein, we report a step-growth annulative π-extension polymerization that allows for the rapid and modular synthesis of cove-type GNRs with pyrene and/or coronene diimide repeating units. The structures and photophysical properties of the separated
Uncovering the Mechanistic Role of HMPA in the Samarium Barbier Reaction
作者:Kimberly A. Choquette、Dhandapani V. Sadasivam、Robert A. Flowers
DOI:10.1021/ja1088925
日期:2010.12.15
for the selective coupling of alkylhalides and ketones by SmI2. Although previous ratestudies have shown that HMPA dramatically accelerates the reduction of alkylhalides over ketones, the basis of this rate acceleration is unknown. In this communication, we report experimental and computational evidence that demonstrate that the selectivity observed in the samarium Barbier reaction is in part a
Catalytic Ni(II) in Reactions of SmI<sub>2</sub>: Sm(II)- or Ni(0)-Based Chemistry?
作者:Kimberly A. Choquette、Dhandapani V. Sadasivam、Robert A. Flowers
DOI:10.1021/ja204287n
日期:2011.7.13
amounts of Ni(II) salts provide enhanced reactivity and selectivity in numerous reactions of SmI(2), but the mechanistic basis for their effect is unknown. We report spectroscopic and kinetic studies on the mechanistic role of catalytic Ni(II) in the samarium Barbier reaction. The mechanistic studies presented herein show that the samarium Barbier reaction containing catalytic amounts of Ni(II) salts is