N-Heterocyclic Carbene Catalyzed Dynamic Kinetic Resolution of Pyranones
作者:Changgui Zhao、Fangyi Li、Jian Wang
DOI:10.1002/anie.201508205
日期:2016.1.26
The dynamickineticresolution of 6‐hydroxypyranones with enals or alkynals through an asymmetric redox esterification is catalyzed by a chiral N‐heterocyclic carbene. The resulting esters are obtained in good to high yields and with high levels of enantio‐ and diastereocontrol. The reaction products are further derivatized to obtain functionalized sugar derivatives and natural products.
A novel synthesis of calix[4]thiophenes and calix[4]furans
作者:Gon-Ann Lee、Wen-Chieh Wang、Minghuey Shieh、Ting-Shen Kuo
DOI:10.1039/c0cc00437e
日期:——
The addition of heteroaryllithium to various ketones followed by dehydration gave 1-(2-heteroaryl)cycloalkenes and (2-hetero- aryl)alkenes. When alkenes were treated with 10 mol% NIS, calix[4]thiophenes and calix[4]furans were obtained in good yields.
Furan-2-yl Anions as γ-Oxo/Hydroxyl Acyl Anion Equivalents Enabled by Iridium-Catalyzed Chemoselective Reduction
作者:Tingting Wang、Rui Miao、Renshi Luo、Jiaxi Xu、Zhanhui Yang
DOI:10.1021/acs.orglett.3c01634
日期:2023.6.30
demonstrated as robust γ-oxo and γ-hydroxyl acyl anion equivalents to convert aldehydes and ketones into trifunctionalized dihydroxyl ketones and hydroxyl diones through sequential nucleophilic addition, Achmatowicz rearrangement, and herein freshly established iridium-catalyzed highly selective transfer hydrogenation reduction.
Divergent approach to the polymaxenolide and pinnaic acid cores
作者:Frank D. Ferrari、Andrew J. Ledgard、Rodolfo Marquez
DOI:10.1016/j.tet.2011.04.047
日期:2011.7
The divergent syntheses of the spirocyclic pyran core of polymaxenolide and the spirocyclic piperidine core of pinnaic acid have been achieved. Our divergent approach takes advantage of highly efficient Achmatowicz and aza-Achmatowicz rearrangements to generate the highly functionalised cores, which are then regioselectively modified. (C) 2011 Elsevier Ltd. All rights reserved.
Mass spectra of some 2- and 3-cycloalkenylfurans and -cycloalkenylthiophenes and their oxyderivatives
作者:Arlene P. Rothwell、Karl V. Wood、Ashok K. Gupta、J. V. N. Vara Prasad