Reductive Coupling of Allylic Esters with Carbonyl Compounds Mediated by the Mischmetall/[SmI2/Pd0cat.′]cat. System
作者:Sédami Médégan、Florence Hélion、Jean-Louis Namy
DOI:10.1002/ejoc.200500291
日期:2005.11
“two-stage catalysis” has been carried out using SmI2 and Pd(PPh3)4 in catalytic amounts together with mischmetall (an alloy of the light lanthanides) as a co-reductant. A catalytic scheme that takes into account previously reported reactions of SmI2/Pd0cat. and mischmetall/SmI2,cat. systems is proposed. It has also been shown that palladium complexes catalyse the addition of organolanthanide species
Regioselective and Stereoselective Copper(I)-Promoted Allylation and Conjugate Addition of <i>N</i>-Boc-2-lithiopyrrolidine and <i>N</i>-Boc-2-lithiopiperidine
作者:Iain Coldham、Daniele Leonori
DOI:10.1021/jo100415x
日期:2010.6.18
regioselectively (SN2 mechanism). Addition to an enone or α,β-unsaturated ester occurs by 1,4-addition. Asymmetric deprotonation of N-Boc-pyrrolidine or dynamic resolution in the presence of a chiral ligand of N-Boc-2-lithiopiperidine followed by the zinc/copper chemistry was successful and gave the allylated pyrrolidine and piperidine products with good enantioselectivity, although use of the copper iodide
铜盐已被筛选的转移金属化和电淬火ñ -叔丁氧羰基-2- lithiopyrrolidine(Ñ -Boc-2- lithiopyrrolidine)和Ñ -Boc-2- lithiopiperidine,通过去质子化而形成Ñ -Boc -吡咯烷和ñ - Boc-哌啶分别。然后,用氯化锌(溶解了氯化锂)进行重金属化,然后进行烯丙基化,生成区域异构体的混合物(S N 2和S N 2'产物),而用碘化铜·TMEDA进行重金属化,则区域选择性地进行烯丙基化(S N2机制)。通过1,4-加成发生烯键或α,β-不饱和酯的加成。N -Boc-吡咯烷的不对称去质子化或在N -Boc-2-lithiopiperidine的手性配体存在下的动态拆分以及随后的锌/铜化学反应是成功的,尽管使用了N -Boc-2-lithiopiperidine的手性配体,但烯丙基化的吡咯烷和哌啶产物具有良好的对映选择性碘化铜的化
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
Pd-Catalyzed Direct C–H Alkenylation and Allylation of Azine <i>N</i>-Oxides
作者:Fares Roudesly、Luis F. Veiros、Julie Oble、Giovanni Poli
DOI:10.1021/acs.orglett.8b00689
日期:2018.4.20
A Pd-catalyzed direct C2-alkenylation of azine N-oxides with allyl acetate is disclosed. The products are formed through an allylation/isomerization cascade process. The use of a tri-tert-butylphosphonium salt as the ligand precursor and KF is mandatory for optimal yields. When cinnamyl acetate is used, the same catalytic system promotes C2-cinnamylation of the azine N-oxide without subsequent isomerization