The C2-symmetric buildingblock 1,2:5,6-di-N,O-carbonyl-1,6-diamino-3,4-O-isopropylidene-d-mannitol can be synthesized from d-mannitol in four steps using a nucleophilic substitution with cyanate and a subsequent cyclization in the final key step. The direct electrochemical oxidation of the resulting dioxazolidinone at 40 mA/cm2 in methanol at graphite electrodes with sodium benzene sulfonate as supporting
的c ^ 2 -对称积木1,2:5,6-二- ñ,ö羰基-1,6-二氨基-3,4- ö异亚丙基d甘露醇可以从d-甘露醇在四个步骤来合成在最后的关键步骤中,用氰酸酯进行亲核取代,然后进行环化。在石墨电极上用苯磺酸钠作为支持电解质,在甲醇中在甲醇中以40 mA / cm 2的浓度对二恶唑烷酮进行直接电化学氧化,生成二甲氧基化产物,该产物可用于各种非对映选择性的酰胺基烷基化反应。在所有情况下,观察到双反立体选择性。
Copper-Catalyzed Regio- and Enantioselective Hydroallylation of 1-Trifluoromethylalkenes: Effect of Crown Ether
作者:Yuki Kojima、Masahiro Miura、Koji Hirano
DOI:10.1021/acscatal.1c02947
日期:2021.9.17
A Cu-catalyzedregio- and enantioselective hydroallylation of 1-trifluoromethylalkenes with hydrosilanes and allylic chlorides has been developed. An in situ generated CuH species undergoes the hydrocupration regio- and enantioselectively to form a chiral α-CF3 alkylcopper intermediate, which then leads to the optically active hydroallylated product. The key to success is the use of not only an appropriate
New synthetic technology for the construction of N-hydroxyindoles and synthesis of nocathiacin I model systems
作者:K.C. Nicolaou、Anthony A. Estrada、Graeme C. Freestone、Sang Hyup Lee、Xavier Alvarez-Mico
DOI:10.1016/j.tet.2007.03.072
日期:2007.7
nucleophilic additions to in situ generated alpha,beta-unsaturated nitrones (III) through carbon-carbon and carbon-heteroatom bond formation. The new synthetic technology was applied to the synthesis of nocathiacinI (1) modelsystems (2 and 3a-c) containing the N-hydroxyindole structural motif.
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
Microwave-Assisted Domino Hydroformylation/Cyclization Reactions: Scope and Limitations
reported to illustrate each sequence. Although apparently more versatile, hydroformylation of alkenes using MW heating is sensitive to the nature of the nucleophiles present in the substrates, evidencing that the conventional heating process cannot be completely replaced by MW irradiation. domino reaction - heterocycles -nucleophilicaddition-cyclization- hemiacetals - Pictet-Spengler reaction