Light-induced Ligation of <i>o</i>-Quinodimethanes with Gated Fluorescence Self-reporting
作者:Florian Feist、Leona L. Rodrigues、Sarah L. Walden、Tim W. Krappitz、Tim R. Dargaville、Tanja Weil、Anja S. Goldmann、James P. Blinco、Christopher Barner-Kowollik
DOI:10.1021/jacs.0c02002
日期:2020.4.29
efficient photoligation system, affording a pro-fluorescent Diels-Alder product which on demand converts into an intensively fluorescent naphthalene via E1-elimination in the presence of catalytic amounts of acid. The Diels-Alder reaction of the photocaged diene (o-quinodimethane ether or thioether, o-QDMs) with electron deficient alkynes is induced by UV or visible light. In contrast to previously reported
Nucleophilic conjugate 1,3-addition of phosphines to oligoynoates
作者:Jie-Cheng Deng、Chih-Wei Kuo、Shih-Ching Chuang
DOI:10.1039/c4cc02870h
日期:——
Herein we have elucidated unusual and unique nucleophilic conjugate 1,3-addition reactions of surveyed oligoynoates toward phosphines through spectroscopic and single crystal X-ray diffraction analyses of three-component reaction products of oligoynoates, phosphines and aldehydes.
Palladium-Catalyzed Asymmetric (3 + 2) Cycloaddition of Vinyl Epoxides with Substituted Propiolates. Enantioselective Formation of 2,3,4-Trisubstituted 2,3-Dihydrofurans
作者:Juan Wang、Yun-Fan Li、Juan Du、Shuai Huang、Chang-Hua Ding、Henry N. C. Wong、Xue-Long Hou
DOI:10.1021/acs.orglett.2c00253
日期:2022.2.25
Alkynyl esters are viable dipolarophiles for the palladium-catalyzedasymmetric (3 + 2) cycloaddition with vinyl epoxides. The chiral dihydrofurans are obtained in high yields and high ee values. The use of a chiral benzylic substituted P,N-ligand is essential. The usefulness of the synthetic method has been demonstrated; 2,3-cis-tetrahydrofuran was also provided.
Synthesis of 4-Pyrones by Formal Hydration of 1,3-Diynones Promoted by 1,4-Addition of Piperidine
作者:Erandi Liyanage Perera、Daesung Lee
DOI:10.1021/acs.orglett.2c02914
日期:2022.9.30
A new approach for the synthesis of 4-pyrones with broader substrate scope and functional group tolerance is described. The reaction proceeds via an initial 1,4-addition by piperidine, followed by nitrogen-assisted 6-endo-dig cyclization and hydrolysis. 1,3-Diynones with nonenolizable electron-withdrawing ketones and nonpropargylic H provide relatively high yields. For substrates with particular R2
描述了一种合成具有更广泛底物范围和官能团耐受性的 4-吡喃酮的新方法。该反应通过哌啶的初始 1,4-加成,然后是氮辅助 6 -endo-dig环化和水解进行。具有非烯醇化吸电子酮和非炔丙基 H 的 1,3-二炔酮提供相对较高的产率。对于具有特定 R 2取代基的底物,分离出 1,4- 或 1,6-加合物,这表明 R 2取代基的空间和电子因素应该对 6 -endo-dig环化产生强烈影响。
六氫-茚并[1,2-b]噁庚因基-4-乙酸酯化合物及其製造方法
申请人:國立陽明交通大學NATIONAL YANG MING CHIAO TUNG UNIVERSITY