公开了前所未有的硒催化炔烃的炔丙基氧化。各种炔丙基膦酸酯和3-链烷酸酯通过不寻常的CC三键迁移和乙烯基碳上的硒烯基化反应,有效地转化为有价值的炔酮。通过烯胺中间体的互变异构和S N 2置换的策略,相似的条件对于乙酰胺的氧化双官能化有效,从而提供了具有高区域选择性的多取代恶唑。机理研究揭示了这些详细的过程。
Catalytic and Asymmetric Process via P<sup>III</sup>/P<sup>V</sup>═O Redox Cycling: Access to (Trifluoromethyl)cyclobutenes via a Michael Addition/Wittig Olefination Reaction
In the present study, we report the first enantioselective and highly efficient phosphine-catalyzed process via a chemoselective in situ phosphine oxide reduction. Starting with 4,4,4-trifluorobutane-1,3-dione and dialkyl acetylenedicarboxylate substrates, highly functionalized fluorinated cyclobutenes were obtained in excellent yields and enantioselectivities. Using the same methodology, CF3-spirocyclobutene
Synthesis of Trisubstituted Allenamides Utilizing 1,2-Rearrangement of Dialkoxyphosphoryl Moiety under Brønsted Base Catalysis
作者:Azusa Kondoh、Ryosuke Ozawa、Masahiro Terada
DOI:10.1246/cl.190489
日期:2019.9.5
A new method for the synthesis of trisubstituted allenamides was developed by utilizing the 1,2-rearrangement of a dialkoxyphosphoryl moiety fromcarbon to nitrogen under Bronsted base catalysis. T...
Pyrolysis of β,γ,β′-trioxo phosphorus ylides: Convenient synthesis of symmetrical and unsymmetrical diacylalkynes
作者:R.Alan Aitken、Hugues Hérion、Amaya Janosi、Swati V. Raut、Shirley Seth、Ian J. Shannon、Fiona C. Smith
DOI:10.1016/s0040-4039(00)73898-6
日期:1993.8
Flash vacuum pyrolysis of a series of 1,2,4-trioxo-3-triphenylphosphoranylidene-butane derivatives, formed by acylation of β-oxo-phosphorus ylides with α-oxo-acid chlorides, results in extrusion of Ph3PO exclusively across the 2,3-position to give diacylalkynes.
η4-(vinylketenimine)iron complexes, pyrroles were produced. Pyrrole formation involved the [2 + 3] cycloaddition of alkyne to the ketenimine moiety, migration of the vinyl group, and decomplexation. Either alkynes bearing two electron-withdrawinggroups, or terminal alkynes with an electron-withdrawinggroup reacted to generate pyrroles.
当缺电子炔烃与 η 4 -(乙烯基烯酮亚胺)铁配合物反应时,产生吡咯。吡咯的形成涉及炔烃与烯酮亚胺部分的 [2 + 3] 环加成、乙烯基的迁移和解络。带有两个吸电子基团的炔烃或带有吸电子基团的末端炔烃反应生成吡咯。
Synthesis of <i>N</i>-Methoxy-<i>N</i>-methyl-β-enaminoketoesters: New Synthetic Precursors for the Regioselective Synthesis of Heterocyclic Compounds
作者:Tobias Persson、John Nielsen
DOI:10.1021/ol0611088
日期:2006.7.1
Weinreb amides react with the lithium or sodium acetylide of ethyl propynoate in a hitherto unexplored acyl substitution-conjugate addition sequence to furnish (E)-N-methoxy-N-methyl-beta-enaminoketoesters. This approach provides a diverse entry to densely functionalized heterocyclic compounds, including pyrazoles through regioselective cyclocondensations with hydrazines in a microwave-assisted reaction