Mild and selective palladium(0)-catalyzed deallylation of allylic amines. Allylamine and diallylamine as very convenient ammonia equivalents for the synthesis of primary amines
Tandem Palladium and Isothiourea Relay Catalysis: Enantioselective Synthesis of α-Amino Acid Derivatives via Allylic Amination and [2,3]-Sigmatropic Rearrangement
作者:Stéphanie S. M. Spoehrle、Thomas H. West、James E. Taylor、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1021/jacs.7b05619
日期:2017.8.30
has been developed for the enantioselective synthesis of α-aminoacid derivatives containing two stereogenic centers from readily accessible N,N-disubstituted glycine aryl esters and allylic phosphates. The optimized process uses a bench-stable succinimide-based Pd precatalyst (FurCat) to promote Pd-catalyzed allylic ammonium salt generation from the allylic phosphate and the glycine aryl ester. Subsequent
Cyclobutadiene cobalt complexes as catalysts for insertion of diazo compounds into X–H bonds
作者:Nikita V. Shvydkiy、Dmitry S. Perekalin
DOI:10.1016/j.mencom.2021.04.022
日期:2021.5
Novel cyclobutadiene cobalt complex with labile naphthalene ligand [(C4Et4)Co(C10H8)]PF6 catalyzes the insertion of ethyl diazoacetate into X–H bondsgiving the corresponding products in 15–75% yields. The reaction proceeds with primary and secondary aliphatic amines, hydrosilanes and triethylamine borane but not with anilines and alcohols.
新型环丁二烯钴配合物与不稳定的萘配体 [(C 4 Et 4 )Co(C 10 H 8 )]PF 6催化重氮乙酸乙酯插入 X-H 键,以 15-75% 的产率得到相应的产物。该反应使用伯和仲脂肪胺、氢硅烷和三乙胺硼烷进行,但不适用于苯胺和醇。
Highly Enantioselective Synthesis of <i>syn</i>-β-Hydroxy α-Dibenzylamino Esters via DKR Asymmetric Transfer Hydrogenation and Gram-Scale Preparation of Droxidopa
of enantiomerically pure syn aryl β-hydroxy α-dibenzylamino esters is reported. The outcome was achieved via dynamic kinetic resolution and asymmetrictransferhydrogenation of aryl α-dibenzylamino β-keto esters. The desired products were obtained in high yields (up to 98%) with excellent diastereoselectivity (>20:1 dr) and enantioselectivity (up to >99% ee). Furthermore, this method was applied for
Iridium Porphyrin Catalyzed N–H Insertion Reactions: Scope and Mechanism
作者:Bernie J. Anding、L. Keith Woo
DOI:10.1021/om400098v
日期:2013.5.13
Ir(TTP)CH3 catalyzed N–H insertion reactions between ethyldiazoacetate (EDA) or methyl phenyldiazoacetate (MPDA) and a variety of aryl, aliphatic, primary, and secondary amines to generate substituted glycine esters with modest to high yields. Aniline substrates generally gave yields above 80%, with up to 105 catalyst turnovers, and without slow addition of the diazo reagent. Good yields were also achieved
Ir(TTP)CH 3催化重氮乙酸乙酯(EDA)或苯基重氮乙酸甲酯(MPDA)与各种芳基,脂肪族,伯和仲胺之间的N–H插入反应,以中等至高收率生成取代的甘氨酸酯。苯胺底物的收率通常超过80%,催化剂的转化率高达10 5,并且没有缓慢添加重氮试剂。尽管在某些情况下需要更高的催化剂负载量和胺的缓慢添加,但脂肪族胺也能获得良好的收率。伯胺与EDA反应生成单,双-插入产品,其中任一个的可在高产率下的化学计量比和反应温度的适当选择有选择地来制备。值得注意的是,混合三取代胺RN(CH通过在伯胺中插入1当量的EDA和1当量的MPDA生成2 CO 2 Et)(CHPhCO 2 Me)。使用底物竞争研究,捕获实验和多种光谱技术检查了N–H插入机制。使用具有EDA或MPDA的成对胺进行的底物竞争研究显示Hammett相关性分别具有ρ= 0.15和ρ + = -0.56的斜率以及k H / k D的动力学同位素比=
Aryne-Mediated [2,3]-Sigmatropic Rearrangement of Tertiary Allylic Amines
3]-sigmatropic rearrangement of quaternary allylic ammonium ylides via in situ activation of tertiary allylicamines with arynes under mild conditions. Using 2-(trimethylsilyl)aryl triflates as aryne precursors, a range of tertiary allylicamines bearing electron-withdrawing groups underwent [2,3]-sigmatropic rearrangement to furnish structurally diverse homoallylic amines in moderate to good yields. The reaction