非消旋仲醇的对映选择性合成已通过铜催化的(Cu(OAc)2 ·H 2 O /(R)-3,4,5-MeO-MeO-MePH-BIPHEP)还原芳基/杂芳基在胶束水溶液中实现酮。这种方法学是一种绿色的方案,可使用贱金属催化剂以及廉价,无害且方便的化学计量氢化物源(PMHS)在温和的条件下(0-22°C)获取对映体富集的醇。形成的仲醇产品的收率好至极好,ee值大于90%。
Lipase-catalyzed esterification in water enabled by nanomicelles. Applications to 1-pot multi-step sequences
作者:Vani Singhania、Margery Cortes-Clerget、Jade Dussart-Gautheret、Bhornrawin Akkachairin、Julie Yu、Nnamdi Akporji、Fabrice Gallou、Bruce H. Lipshutz
DOI:10.1039/d1sc05660c
日期:——
Esterification in an aqueous micellar medium is catalyzed by a commerciallyavailable lipase in the absence of any co-factors. The presence of only 2 wt% designer surfactant, TPGS-750-M, assists in a 100% selective enzymatic process in which only primary alcohols participate (in a 1 : 1 ratio with carboxylic acid). An unexpected finding is also disclosed where the simple additive, PhCF3 (1 equiv. vs
Regioselective electrochemical radical cascade cyclization of internal alkynes to selenated and trifluoromethylated dihydropyran
作者:Mingming Yu、Tiantian Huang、Lin Zhang、Muhammad Shabbir、Yuhan Gao、Yi-Hung Chen、Hong Yi、Aiwen Lei
DOI:10.1007/s11426-023-1703-8
日期:2023.11
trifluoromethylated DHP compounds. The reaction proceeded smoothly under mild electrolysis conditions. The broad substrate scope (>50 examples) and scalablesynthesis demonstrated the complexity-building potential of the strategy. Initial mechanistic studies reveal that cyclization may involve a radical process. This protocol may promote the further development of diversified synthesis of multi-substituted dihydropyran
Three Component
<i>syn</i>
‐1,2‐Arylmethylation of Internal Alkynes**
作者:Shubham Dutta、Akhila K. Sahoo
DOI:10.1002/anie.202300610
日期:2023.3.13
A regio- and stereoselective Pd-catalyzed three-component syn-1,2-arylmethylation of internalalkynes is reported. A library of methyl containing tetra-substituted olefins was successfully built using readily available and bench-stable coupling partners, iodo-arenes, and methyl boronic acid.
remote functionalizations based on alkene isomerization. In contrast, protocols based on alkyne isomerization are comparatively rare. Herein, we report a general Pd-catalyzed long-range isomerization of alkynyl alcohols. Starting from aryl-, heteroaryl-, or alkyl-substituted precursors, the optimized system provides access preferentially to the thermodynamically more stable α,β-unsaturated aldehydes
Coupling reactions of aryl bromides with 1-alkynols catalysed by a tetraphosphine/palladium catalyst
作者:Marie Feuerstein、Henri Doucet、Maurice Santelli
DOI:10.1016/j.tetlet.2003.12.128
日期:2004.2
cis. cis, cis-1, 2, 3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C3H5)](2) system catalyses efficiently the coupling reactions of aryl halides with a variety of alkynols such as propargy] alcohol, but-1-yn-4-ol, pent-1-yn-5-ol or hex-1-yn-6-ol. The catalyst can be used at lowloading. Higher reaction rates were observed in the presence of but-1-yn-4-ol, pent-1-yn-5-ol or hex-1-yn-6-ol than with propargy] alcohol. The protection of the alcohol functions as an ether or a silyloxy group led generally to similar or better results than the reactions performed with the unprotected alcohols. (C) 2004 Elsevier Ltd. All rights reserved.