Synthesis of Benzo[<i>b</i>]fluoranthenes and Spiroacridines from Fluorene-Derived Alkenes and <i>N</i>-Arylimines via a Tandem Reaction with Benzynes
作者:Weihua Wang、Hongwei Wan、Guangfen Du、Bin Dai、Lin He
DOI:10.1021/acs.orglett.9b00659
日期:2019.5.17
Two tandem processes involving the cycloaddition of benzynes have been developed for the synthesis of polyaromatic hydrocarbons. Benzynes react with fluorene-derived alkenes through a tandem Diels–Alder reaction/dehydrogenation process to afford benzo[b]fluoranthenes in 35–87% yields. In addition, an unprecedented [2 + 2] cycloaddition/ring-opening sequence of benzynes and fluorene-derived N-arylimines
已经开发了涉及联苯的环加成的两个串联方法来合成聚芳族烃。通过串联Diels-Alder反应/脱氢过程,苯并zy与芴衍生的烯烃反应,以35-87%的收率得到苯并[ b ]芴。此外,前所未有的[2 + 2]苯并炔和芴衍生的N-芳基嘧啶的环加成/开环顺序可轻松获得螺cr啶,收率为38-79%。
Hydride, Hydrogen, Proton, and Electron Affinities of Imines and Their Reaction Intermediates in Acetonitrile and Construction of Thermodynamic Characteristic Graphs (TCGs) of Imines as a “Molecule ID Card”
作者:Xiao-Qing Zhu、Qiao-Yun Liu、Qiang Chen、Lian-Rui Mei
DOI:10.1021/jo902332n
日期:2010.2.5
A series of 61 imines with various typical structures were synthesized, and the thermodynamic affinities (defined as enthalpy changes or redox potentials in this work) of the imines to abstract hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the imines to abstract hydrogen atoms and protons, and the thermodynamic affinities of the hydrogen adducts of the imines to abstract electrons in acetonitrile were determined by using titration calorimetry and electrochemical methods. The pure heterolytic and homolytic dissociation energies of the C = N pi-bond in the imines were estimated. The polarity of the C = N double bond in the imines was examined using a linear free-energy relationship. The idea of a thermodynamic characteristic graph (TCG) of imines as an efficient "Molecule ID Card" was introduced. The TCG can be used to quantitatively diagnose and predict the characteristic chemical properties of imines and their various reaction intermediates as well as the reduction mechanism of the imines. The information disclosed in this work could not only supply a gap of thermodynamics for the chemistry of imines but also strongly promote the fast development of the applications of imines.