Enabling the Rearrangement of Unactivated Allenes to 1,3-Dienes by Use of a Palladium (0)/Boric Acid System
作者:Marc Kimber、Yassir Al-Jawaheri、Matthew Turner
DOI:10.1055/s-0036-1591580
日期:2018.6
injection ESI-HRMS analysis we have detected and identified key π-allylpalladium complexes that support the addition of the palladiumhydridecomplex to the allene. A redox neutral rearrangement of an allene to a 1,3-diene by means of a unique palladiumhydridecomplex is reported. The palladiumhydridecomplex is generated from a simple Pd0 source and boric acid [B(OH)3], which is typically identified
Regioselective aerobic oxidative Heck reactions with electronically unbiased alkenes: efficient access to α-alkyl vinylarenes
作者:Changwu Zheng、Shannon S. Stahl
DOI:10.1039/c5cc05312a
日期:——
A Pd(TFA)2/2,9-dimethyl-1,10-phenanthroline catalyst enables branched-selective oxidative coupling of arylboronic acids and electronically unbiased alkenes.
Synthesis of 1,3-Dienes via a Sequential Suzuki–Miyaura Coupling/Palladium-Mediated Allene Isomerization Sequence
作者:Yassir Al-Jawaheri、Marc C. Kimber
DOI:10.1021/acs.orglett.6b01841
日期:2016.7.15
synthesis of 1,3-dienes by a sequential process consisting of a palladium-catalyzed, base-free, Suzuki–Miyauracoupling/isomerization sequence. This sequence couples boronic acids with propargyl alcohols, generating the requisite allene in situ, followed by conversion of the unactivated allene to its 1,3-diene via a hydro-palladation/dehydro-palladation process. This process is general for a range of boronic
我们报告了一种由钯催化,无碱,Suzuki-Miyaura偶联/异构化序列组成的顺序过程,用于合成1,3-二烯的简便方法。该序列将硼酸与炔丙醇偶合,在原位生成必需的丙二烯,然后通过加氢palpalation /脱氢palpalation过程将未活化的alene转化为其1,3-二烯。对于一系列硼酸,包括具有给电子和吸电子基团的硼酸,以及杂芳基硼酸,该方法是通用的。该过程的关键是无碱Suzuki-Miyauru偶联的硼酸副产物,该副产物可生成异构化所需的钯-氢络合物[H-Pd II -OB(OH)2 ]。
Copper and neocuproine catalysed synthesis of cinnamyl ether derivatives directly from secondary and tertiary cinnamyl alcohols
作者:Zhenjiao Yang、Yongsheng Zhang、Xingxian Lv、Yang Yang、Chunhao Jiang、Xiaoyan He、Guoliang Chen、Gang Huang、Xiuhong Lu
DOI:10.1039/d2gc01602h
日期:——
The skeletons of secondary and tertiary cinnamyl alcohols are found ubiquitously in natural products and commercial drugs. Due to the easy dehydration of their structures, the etherification of such compounds is often difficult. A new method for the synthesis of secondary and tertiary cinnamyl ether derivatives, employing copper sulfate pentahydrate (CuSO4·5H2O) as a catalyst and neocuproine as a ligand
Iron-Catalyzed Cross-Coupling of α-Allenyl Esters with Grignard Reagents for the Synthesis of 1,3-Dienes
作者:Wei-Jun Kong、Simon N. Kessler、Haibo Wu、Jan-E. Bäckvall
DOI:10.1021/acs.orglett.2c03916
日期:2023.1.13
Structurally diverse 1,3-dienes are valuable building blocks in organic synthesis. Herein we report the iron-catalyzed coupling between α-allenyl esters and Grignard reagents, which provides a fast and practical approach to a variety of complex substituted 1,3-dienes. The reaction involves an inexpensive iron catalyst, mild reaction conditions, and provides easy scale up.