已经开发了一种用于将容易获得的外消旋、支链芳族烯丙酯转化为支链烯丙胺、醚和烷基的催化方案。钯催化的支链烯丙基酯异构化为末端烯丙基酯,然后依次进行铱催化的烯丙基取代,以良好的收率得到支链烯丙基产物,具有高区域异构和对映异构选择性。富电子和缺电子支化烯丙基酯均产生 >90% ee 的产物。对于来自乙酸2-噻吩酯和碳酸二烯酯的反应的产物,也观察到高对映体过量。
已经开发了一种用于将容易获得的外消旋、支链芳族烯丙酯转化为支链烯丙胺、醚和烷基的催化方案。钯催化的支链烯丙基酯异构化为末端烯丙基酯,然后依次进行铱催化的烯丙基取代,以良好的收率得到支链烯丙基产物,具有高区域异构和对映异构选择性。富电子和缺电子支化烯丙基酯均产生 >90% ee 的产物。对于来自乙酸2-噻吩酯和碳酸二烯酯的反应的产物,也观察到高对映体过量。
Rhodium-Catalyzed Asymmetric N−H Functionalization of Quinazolinones with Allenes and Allylic Carbonates: The First Enantioselective Formal Total Synthesis of (−)-Chaetominine
作者:Yirong Zhou、Bernhard Breit
DOI:10.1002/chem.201705059
日期:2017.12.22
An unprecedented asymmetric N−H functionalization of quinazolinones with allenes and allylic carbonates was successfully achieved by rhodium catalysis with the assistance of chiral bidentate diphosphine ligands. The high efficiency and practicality of this method was demonstrated by a low catalyst loading of 1 mol % as well as excellent chemo‐, regio‐, and enantioselectivities with broad functional
Ï-Allylic azidation of allyl esters was performed with an amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported phosphine-palladium complex in water under heterogeneous conditions to give allyl azides in good to high yields. The polymeric palladium catalyst can be readily recovered and recycled.
Co‐catalyzedallylic substitution reactions have received little attention, arguably because of the lack of any known advantage of Co catalysis over either Rh or Ir catalysis. Described here is a general and regioselective Co‐catalyzedallylicalkylation using an in situ catalyst activation by organophotoredox catalysis. This noble‐metal‐free catalytic system exhibits unprecedentedly high reactivities
Substituted Pyridylamide Ligands in Microwave-Accelerated Mo(0)-Catalysed Allylic Alkylations
作者:Christina Moberg、Oscar Belda
DOI:10.1055/s-2002-33345
日期:——
bis-pyridylamides were prepared by microwave accelerated nucleophilic substitution of the 4-and 6-halo substituted derivatives of the parent ligand la. The ligands were used in the asymmetric allylation of cinnamyl carbonate catalysed by Mo(0) in which the 4-chloro- and 4-pyrrolidyl substituted ligand derivatives exhibited high regioselectivity (74:1 and 88:1. respectively) and enantioselectivity (96% ee), whereas
π-Allylic Sulfonylation in Water with Amphiphilic Resin-Supported Palladium-Phosphine Complexes
作者:Yasuhiro Uozumi、Toshimasa Suzuka
DOI:10.1055/s-2008-1067096
日期:——
with an amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported phosphine-palladium complex in water as a single reaction medium under heterogeneous conditions to give allyl sulfones in good to high yields. Catalyticasymmetricallylic substitution of cycloalkenyl esters also took place in water using a PS-PEG resin-supported chiral imidazo-indolephosphine-palladium complex to give cycloalkenyl
用两亲性聚苯乙烯-聚(乙二醇)(PS-PEG)树脂负载的膦-钯配合物在水中作为单一反应介质在非均相条件下进行烯丙基酯与芳基亚磺酸钠的 π-烯丙基取代,得到良好的烯丙基砜到高产。环烯基酯的催化不对称烯丙基取代也在水中使用 PS-PEG树脂负载的手性咪唑-吲哚膦-钯络合物进行,得到高达 81% ee 的环烯基砜。