Enantioselective alkynylations of aromatic and aliphatic aldehydes catalyzed by terpene derived chiral amino alcohols
作者:Cian Christopher Watts、Praveen Thoniyot、Lacie C. Hirayama、Talia Romano、Bakthan Singaram
DOI:10.1016/j.tetasy.2005.03.036
日期:2005.5
Enantioselective alkynyl zinc additions to aromatic and aliphatic aldehydes have been studied using terpene derived chiral amino alcohol ligands. The limonene derived amino alcohol (1R,2R,5S)-2-methyl-5-(1-methylethenyl)-2-(1-pyrrolidinyl)cyclohexanol gave the most promising results. Chiral propargylic alcohols were obtained in good yields and moderate enantioselectivities (up to 60%).
Synthesis of 1,6-Dihydropyridine-3-carbonitrile Derivatives <i>via</i> Lewis Acid-Catalyzed Annulation of Propargylic Alcohols with (<i>E</i>)-3-Amino-3-phenylacrylonitriles
作者:Li-Juan Du、Yuecheng Zhang、Hong-Yu Zhang、Guohui Yin、Xiao-Yan Wang、Jiquan Zhao、Ya-Ping Han
DOI:10.1021/acs.joc.0c01171
日期:2020.8.7
acid-catalyzed, highly efficient, practical, and atom-economical protocol for the synthesis of functionalized 1,2-dihydropyridine-3-carbonitrile derivatives in the presence of Bi(OTf)3 (10 mol %) in tetrahydrofuran (2.0 mL) at 80 °C for 8 h in air is described, starting from readily accessed propargylic alcohols and (E)-3-amino-3-phenylacrylonitriles. This cycloaddition protocol, which is scalable and
1,1′-Binaphthyl ligands with bulky 3,3′-tertiaryalkyl substituents for the asymmetric alkyne addition to aromatic aldehydes
作者:Qin Wang、Shan-Yong Chen、Xiao-Qi Yu、Lin Pu
DOI:10.1016/j.tet.2007.03.080
日期:2007.5
The BINOL ligand (R)-2 that contains bulky 3,3'-tertiaryalkyl groups shows improved catalytic properties than the previously reported 3,3'-substituted BINOL ligands in the asymmetric alkyne addition to aromatic aldehydes. It can catalyze the phenylacetylene addition to aromatic aldehydes with high enantioselectivity (86 - 94% ee) and good yields without using Ti(O(i)Pr)(4) and a Lewis base additive
yields in a totally selective manner. In this way, bis(triflyl)flavones, bis(triflyl)thioflavones, bis(triflyl)selenoflavones, (triflyl)benzothienopyrans, (triflyl)benzoselenophenopyrans, (triflyl)vinyl aurones, and (triflyl)pyranoindoles were constructed. Conceivable mechanistic pathways were suggested on the basis of the isolation of several intermediates and the results from control experiments
可以通过Tf 2 C = CH 2激活功能化的炔酮,原位生成,形成两性离子物质。这些物种以分子内方式被数个亲核试剂捕获,以发散的方式产生两种主要类型的三苯甲酮。通过对反应温度的微调,以完全选择的方式以合理的收率获得了双(triflyl)-6元或(triflyl)-5元稠合杂环。以此方式,构建了双(三氟乙)黄酮,双(三氟乙)硫代黄酮,双(三氟乙)硒代黄酮,(三氟乙)苯并噻吩并吡喃,(三氟苯)苯并硒基苯并吡喃,(三氟乙)乙烯基金酮和(三氟乙)吡喃并吲哚。根据几种中间体的分离和对照实验的结果,提出了可能的机理途径。
Regioselective Synthesis of Heteroatom-Functionalized Cyclobutene-triflones and Cyclobutenones
synthesis of a vast variety of heteroatom‐containing cyclobutene‐triflones [bis(trifluoromethylsulfonyl)cyclobutenes] and cyclobutenones has been developed starting from heteroatom‐substituted alkynes and a pyridinium salt (a latent Tf2C=CH2 source). This powerful methodology, involving cyclization reactions, allows for the selective preparation of oxygen‐, nitrogen‐, bromine‐, chlorine‐, iodine‐, sulfur‐
从杂原子取代的炔烃和吡啶鎓盐(潜在的Tf 2 C = CH 2来源)开始,开发了可控制的无金属合成各种杂原子的环丁烯-triflones [双(三氟甲基磺酰基)环丁烯]和环丁烯酮。。这种强大的方法涉及环化反应,可以选择性地制备氧,氮,溴,氯,碘,硫,硒,碲,磷和硅官能化的环丁烯衍生物。