Sequential Catalytic Isomerization and Allylic Substitution. Conversion of Racemic Branched Allylic Carbonates to Enantioenriched Allylic Substitution Products
作者:Shashank Shekhar、Brian Trantow、Andreas Leitner、John F. Hartwig
DOI:10.1021/ja0644273
日期:2006.9.1
A catalytic protocol for the conversion of readily accessible racemic, branched aromatic allylic esters to branched allylic amines, ethers, and alkyls has been developed. Palladium-catalyzed isomerization of branched allylic esters to terminal allylic esters, followed by sequential iridium-catalyzed allylic substitution, gave the branched allylic products in good yield with high regioisomeric and enantiomeric
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 Enantioselective Hydroamination of Alkynes with Indolines
作者:Qing-An Chen、Zhiwei Chen、Vy M. Dong
DOI:10.1021/jacs.5b05200
日期:2015.7.8
alkynes via tandem rhodium catalysis gives branched N-allylic indolines with high regio- and enantioselectivity. An acid switch provides access to the linear isomer in preference to the branched isomer by an isomerization mechanism. Mechanistic studies suggest formation of an allene intermediate, which undergoes hydroamination to generate allylic amines instead of the enamine or imine products typically observed
Iridium-Catalyzed, Asymmetric Amination of Allylic Alcohols Activated by Lewis Acids
作者:Yasuhiro Yamashita、Apsara Gopalarathnam、John F. Hartwig
DOI:10.1021/ja0730718
日期:2007.6.1
enantioselective amination of allylic alcohols with Lewis acid activators to form branched allylic amine products is reported. The reactions of arylamines, benzylic amines, and secondary aliphatic amines in the presence of Nb(OEt)5 as activator occurred with high regioselectivities and high enantioselectivities. These results led to the development of Ir-catalyzed reactions of allylic alcohol with arylamines
报道了烯丙醇与路易斯酸活化剂的直接、Ir 催化、区域和对映选择性胺化反应,形成支链烯丙胺产物。在 Nb(OEt)5 作为活化剂存在下,芳胺、苄胺和脂肪仲胺的反应具有高区域选择性和高对映选择性。这些结果导致了烯丙醇与芳胺和 BPh3 作为催化量的活化剂的 Ir 催化反应的发展。这些反应是烯丙醇对映选择性取代的罕见例子。它们是烯丙醇取代以从单取代烯丙醇产生支化取代产物以及烯丙醇与胺亲核试剂的对映选择性取代的特别不寻常的例子。
Ir-catalyzed asymmetric allylic amination using chiral diaminophosphine oxides
An Ir-catalyzed asymmetric allylic amination using chiral diaminophosphine oxide is described. Asymmetric allyno amination of terminal allylic carbonates proceeded in the presence of 2 mol % of Ir catalyst, 2 mol % of chiral diaminophosphine oxide, 5 mol % of NaPF6, and BSA, affording the chiral branched allylic amines in up to 95% cc. (c) 2006 Elsevier Ltd. All rights reserved.
Ruthenium-Catalyzed Regio- and Enantioselective Allylic Amination of Racemic 1-Arylallyl Esters
The regio- and enantioselective allylic amination of racemic monosubstituted allylic esters, such as 1-arylallyl acetates, with cyclic secondary amines has been accomplished. The RuCl3/(S,S)-ip-pybox catalyst system has effectively catalyzed the reaction to afford the enantiomerically enriched branch-type allylic amines with perfect regioselectivity and high enantioselectivity.