Development of a [2 + 2]-Nitroso/Alkene Cycloaddition Using Sodium Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate Catalyst: Controlled Chemoselectivity of Two Equilibrating Isomeric Intermediates
作者:Jia-Xuan Chen、Prakash D. Jadhav、Ching-Nung Chen、Rai-Shung Liu
DOI:10.1021/acs.orglett.1c01987
日期:2021.8.20
Sodium tetrakis[3,5-bis(trifluoromethyl)-phenyl]borate (NaBArF) catalyzes the [2 + 2] cycloaddition of 1,4-disubstituted cyclopenta-1,3-dien-2-yl esters with nitrsobenzene in toluene, affording two isolable regioisomers of 6-oxa-7-azabicyclo[3.2.0] heptanes, which thermally rearrange into the same 4-aminocyclopent-1-en-3-ones. In the case of 4-substituted cyclopenta-1,3-dien-2-yl esters, their initial
Efficient Synthesis of Cyclopentenones from Enynyl Acetates via Tandem Au(I)-Catalyzed 3,3-Rearrangement and the Nazarov Reaction
作者:Liming Zhang、Shaozhong Wang
DOI:10.1021/ja057327q
日期:2006.2.1
A highly efficient method for the synthesis of versatilecyclopentenones from readily available enynyl acetates via tandem Au(I)-catalyzed 3,3-rearrangement and the Nazarov reaction is developed. Significant substrate flexibility and excellent control of the double bond position in the cyclopentenone ring render this an attractive method for cyclopentenonesynthesis.
type of structure units is full of challenge due to their congested chemical environment. Herein, we report a new gold(I) self-relay catalysis merging [3,3]-sigmatropic rearrangement/Nazarov cyclization with allylic alkylation starting from 1,3-enyne acetates and allylic alcohols, producing a wide range of synthetically important allyl cyclopentenones with an all-carbon quaternary stereocenter in good
Gold(I)-Catalyzed Highly Diastereo- and Enantioselective Constructions of Bicyclo[3.2.1]oct-6-ene Frameworks via (4 + 3)-Cycloadditions
作者:Sudhakar Dattatray Tanpure、Tung-Chun Kuo、Mu-Jeng Cheng、Rai-Shung Liu
DOI:10.1021/acscatal.1c04483
日期:2022.1.7
1]oct-6-ene frameworks involves gold-catalyzed (4 + 3)-cycloadditions between 2-(1-alkynyl)-2-alken-1-ones and substituted cyclopentadienes; diastereoselectivity (dr >25:1) and enantioselectivity (up to 99.9% ee) are achieved with a chiral gold catalyst. Our DFT calculations suggest a three-step ionic mechanism for the cycloadditions of gold-containing 1,3-dipoles with cyclopentadienes, in which an exo-spatial
An efficientsynthetic approach for the synthesis of cyclopentenones containing a C–C stereocenter that relies on gold(I)-catalyzed Nazarov-type cyclization/1,6-addition of 1,3-enyne esters with p-quinone methides (p-QMs) is described. This tandem transformation exhibited a satisfactory substrate scope and passable functional group compatibility, providing a novel protocol for rapid assembly cyclopentenones
一种有效合成含有 C-C 立构中心的环戊烯酮的合成方法,该方法依赖于金 (I) 催化的纳扎罗夫型环化/1,3-烯炔酯与对醌甲基化物的 1,6-加成( p -QMs )进行了描述。这种串联转化表现出令人满意的底物范围和良好的官能团兼容性,为在温和反应条件下以良好至优异的产率快速组装环戊烯酮提供了新的方案。