基于3-(苯并咪唑-2-基)喹喔啉-2(1 H)-与1,2-的环收缩,已开发出一种高效且通用的具有两个苯并咪唑片段的喹喔啉衍生物的合成方法。二氨基苯及其各种类型的取代和稠合衍生物。由于分子间和分子内过程,涉及桥联和相邻碳原子的大多数双-苯并咪唑基喹喔啉信号的几种形式之间的自缔合,质子交换,构象和/或互变异构交换,且NMR光谱中的苯并咪唑片段变宽。苯并咪唑片段与分子的喹喔啉核心之间的共轭作用比喹喔啉衍生物(10c)与其噻二唑[ f ]-(17)和吡咯并[ a ]-(19)环化了衍生物,导致整个分子的平面度更大。
Darzens reaction in the synthesis of 3-(α-chloroalkyl)quinoxalin-2(1H)-ones
摘要:
A two-stage method was developed for the synthesis of 3-(alpha-chloroalkyl- and alpha-chlorophenylalkyl)-quinoxalin-2(1H)-ones proceeding from methyl chloroalkyl- and chlorophenylalkylpyruvates obtained by Darzens reaction from methyl dichloroacelate and appropriate aldehydes in the presence of t-BuOK.
Dynamic Kinetic Asymmetric Cross-Benzoin Additions of β-Stereogenic α-Keto Esters
作者:C. Guy Goodman、Jeffrey S. Johnson
DOI:10.1021/ja508521a
日期:2014.10.22
The dynamickineticresolution of β-halo α-keto esters via an asymmetric cross-benzoin reaction is described. A chiral N-heterocycliccarbenecatalyzes the umpolung addition of aldehydes to racemic α-keto esters. The resulting fully substituted β-halo glycolic ester products are obtained with high levels of enantio- and diastereocontrol. The high chemoselectivity observed is a result of greater electrophilicity
Enantioconvergent Synthesis of Functionalized γ-Butyrolactones via (3 + 2)-Annulation
作者:C. Guy Goodman、Morgan M. Walker、Jeffrey S. Johnson
DOI:10.1021/ja511701j
日期:2015.1.14
A dynamic kineticresolution of β-halo α-keto esters in an asymmetric homoenolate reaction is described. A chiral N-hetereocyclic carbene catalyzes the a3 → d3-umpolung addition of α,β-enals to racemic α-keto esters, forming γ-butyrolactones with threecontiguousstereocenters. The addition occurs with high regio-, diastereo-, and enantiocontrol. This methodology constitutes an intermolecular DKR process
Diastereoselective Organocatalytic Addition of α-Angelica Lactone to β-Halo-α-ketoesters
作者:Jessica A. Griswold、Matthew A. Horwitz、Leslie V. Leiva、Jeffrey S. Johnson
DOI:10.1021/acs.joc.6b03059
日期:2017.2.17
A quinidine-catalyzed diastereoselective addition of α-angelica lactone to β-halo-α-ketoesters is reported. The α-angelica lactone displays unusual regioselectivity in this reaction, acting as a nucleophile at the α-position to provide fully substituted glycolic esters with three contiguous stereocenters. Subsequent diastereoselective hydrogenation provides an additional stereocenter within the lactone
作者:V. A. Mamedov、D. F. Saifina、E. A. Berdnikov、I. Kh. Rizvanov
DOI:10.1007/s11172-007-0334-3
日期:2007.10
Upon treatment with acetic acid, 3-(2-phenyl-1-selenocyanatoethyl)-, 3-(3-phenyl-1-selenocyanatopropyl)quinoxalin-2(1H)-ones and their thio analogs undergo intramolecular condensation to form selenazolo-and thiazolo[3,4-a]quinoxalines.