Contra-Thermodynamic, Photocatalytic <i>E</i>
→<i>Z</i>
Isomerization of Styrenyl Boron Species: Vectors to Facilitate Exploration of Two-Dimensional Chemical Space
作者:John J. Molloy、Jan B. Metternich、Constantin G. Daniliuc、Allan J. B. Watson、Ryan Gilmour
DOI:10.1002/anie.201800286
日期:2018.3.12
Designing strategies to access stereodefined olefinic organoboron species is an important synthetic challenge. Despite significant advances, there is a striking paucity of routes to Z‐α‐substituted styrenyl organoborons. Herein, this strategic imbalance is redressed by exploiting the polarity of the C(sp2)−B bond to activate the neighboring π system, thus enabling a mild, traceless photocatalytic isomerization
Fully palladium/copper catalytic oxidative cross-coupling of acrylates with α-methylstyrene was performed in a DMSO/AcOH (1:1) mixture at 60 °C in the air. This improves previous procedures which employed stoichiometric amounts of copper and oxygen. Thus various acrylates were effectively coupled to α-methylstyrene giving the expected compounds in moderate to good yields (44%–65%) as a mixture of E and Z isomers.
丙烯酸酯与 α-甲基苯乙烯的全钯/铜催化氧化交叉偶联反应是在 DMSO/AcOH (1:1) 混合物中于 60 °C 空气中进行的。这改进了以往采用铜和氧的化学计量方法。因此,各种丙烯酸酯都能有效地与α-甲基苯乙烯偶联,并以中等至良好的收率(44%-65%)得到预期的 E 和 Z 异构体混合物。
Xu, Yun-He; Lu, Jun; Loh, Teck-Peng, Journal of the American Chemical Society, 2009, vol. 131, p. 1372 - 1373
作者:Xu, Yun-He、Lu, Jun、Loh, Teck-Peng
DOI:——
日期:——
STAKEM F. G.; HECK R. F., J. ORG. CHEM., 1980, 45, NO 18, 3584-3593