Iridium-Catalyzed Allylic Vinylation and Asymmetric Allylic Amination Reactions with<i>o</i>-Aminostyrenes
作者:Ke-Yin Ye、Hu He、Wen-Bo Liu、Li-Xin Dai、Günter Helmchen、Shu-Li You
DOI:10.1021/ja2092954
日期:2011.11.23
developed. Mechanistic studies of the allylic vinylation reaction have been carried out, and the results suggest that the leaving group of the allylic precursor plays a key role in directing the reaction pathway. Screening of various allylic precursors showed that Ir-catalyzed reactions of allyl diethyl phosphates with o-aminostyrene derivatives proceed via an allylicamination pathway. A subsequent ring-closing
已经实现了烯丙基碳酸酯与邻氨基苯乙烯衍生物的 Ir 催化烯丙基乙烯基化反应,提供了跳过的 (Z,E)-二烯衍生物。以 (E)-but-2-ene-1,4-diyl二碳酸二甲酯为底物,通过 Ir 催化的多米诺烯丙基乙烯基化/分子内烯丙基胺化反应有效地对映选择性合成 1-苯并氮杂衍生物。已经进行了烯丙基乙烯基化反应的机理研究,结果表明烯丙基前体的离去基团在指导反应途径中起着关键作用。对各种烯丙基前体的筛选表明,Ir 催化的磷酸烯丙酯与邻氨基苯乙烯衍生物的反应是通过烯丙基胺化途径进行的。随后胺化产物的闭环复分解 (RCM) 反应产生了一系列对映异构富集的 1,2-二氢喹啉衍生物。(-)-angustureine 的不对称全合成表明了它们的效用。
Free Radical-Mediated Tandem Reaction of Dehydroamino Acid Derivative with π-Allyl Palladium Complex: Synthesis of α,α-Disubstituted Amino Acids
作者:Yoshiji Takemoto、Hideto Miyabe、Ryuta Asada、Kazumasa Yoshida
DOI:10.1055/s-2004-815407
日期:——
The diethylzinc-promoted reaction of dehydroamino acid derivative with electrophilic π-allylpalladium complex proceeded smoothly to afford α,α-disubstituted amino acids via a tandem radical and anionic carbon-carbon bondforming processes.
Synthesis of α,α-disubstituted amino acids based on tandem reaction of dehydroamino acid derivatives
作者:Hideto Miyabe、Ryuta Asada、Yoshiji Takemoto
DOI:10.1016/j.tet.2004.10.104
日期:2005.1
all-substituted sp3-hybridized carbon-center was investigated via tandem reaction of dehydroamino acid derivatives. The diethylzinc-promoted reaction of dehydroamino acid derivatives with acid anhydride or π-allylpalladium complex proceeded smoothly to afford α,α-disubstituted amino acids via a radical and anionic carbon–carbon bond-forming processes. The tandem reductive reaction of N-phthaloyl dehydroalanine
The asymmetric synthesis of beta-substituted alpha-amino acids with use of iridium-catalyzedallylicsubstitution was described. The Ir-catalyzed allylicsubstitution of diphenylimino glycinate with allylic phosphates proceeded smoothly even at 0 degrees C and gave branch products with high enantioselectivity (up to 97% ee), when chiral bidentate phosphite bearing the 2-ethylthioethyl group was employed