Palladium(0)-Mediated Rapid Methylation and Fluoromethylation on Carbon Frameworks by Reacting Methyl and Fluoromethyl Iodide with Aryl and Alkenyl Boronic Acid Esters: Useful for the Synthesis of [<sup>11</sup>C]CH<sub>3</sub>C- and [<sup>18</sup>F]FCH<sub>2</sub>C-Containing PET Tracers (PET=Positron Emission Tomography)
methylation and fluoromethylation on aryl and alkenyl frameworks by using methyl and fluoromethyl iodide with an organoboronic acid ester has been developed under the simple and mild conditions of [Pd2(dba)3]/P(o‐CH3C6H4)3/K2CO3 (dba= dibenzylideneacetone) in DMF at 60 °C for 5 min (see scheme). This boron protocol provides a firm chemical basis for the synthesis of 11C‐ and 18F‐incorporated PET tracers.
在简单温和的 [Pd 2 (dba) 3 ]/P( o ‐CH )条件下,开发了一种新的合成方法,利用甲基和氟甲基碘与有机硼酸酯在芳基和烯基骨架上进行快速甲基化和氟甲基化3 C 6 H 4 ) 3 /K 2 CO 3 (dba=二亚苄基丙酮)在DMF中在60°C下5分钟(参见方案)。该硼方案为合成11 C 和18 F 的 PET 示踪剂提供了坚实的化学基础。
Catalytic Enantioselective Synthesis of 1,4‐Keto‐Alkenylboronate Esters and 1,4‐Dicarbonyls
作者:Michael Z. Liang、Simon J. Meek
DOI:10.1002/anie.201907757
日期:2019.10
catalytic enantioselective method for the synthesis of 1,4-keto-alkenylboronate esters by a rhodium-catalyzed conjugate addition pathway is disclosed. A variety of novel, bench-stable alkenyl gem-diboronate esters are synthesized. These easily accessible reagents react smoothly with a collection of cyclic α,β-unsaturatedketones, generating a new C-C bond and stereocenter. Products are isolated in up to
1,3‐Difunctionalizations of [1.1.1]Propellane via 1,2‐Metallate Rearrangements of Boronate Complexes
作者:Songjie Yu、Changcheng Jing、Adam Noble、Varinder K. Aggarwal
DOI:10.1002/anie.201914875
日期:2020.3.2
structures is via multicomponent ring-opening reactions of [1.1.1]propellane. However, challenges associated with these transformations mean that difunctionalized BCPs are more commonly prepared by multistep reaction sequences with BCP-halide intermediates. Herein, we report three- and four-component 1,3-difunctionalizations of [1.1.1]propellane with organometallic reagents, organoboronic esters, and a variety
Oxidative Palladium(II) Catalysis: A Highly Efficient and Chemoselective Cross-Coupling Method for Carbon−Carbon Bond Formation under Base-Free and Nitrogenous-Ligand Conditions
作者:Kyung Soo Yoo、Cheol Hwan Yoon、Kyung Woon Jung
DOI:10.1021/ja063710z
日期:2006.12.1
For instance, oxidativepalladium(II) catalysis is effective with highly substituted alkenes and cyclic alkenes, which are known to be incompatible with other known catalytic conditions. Most examined reactions progressed smoothly to completion at low temperatures and in short times. These interesting results provide mechanistic insights and utilities for a new paradigm of palladium catalytic cycles
我们在此报告了氧促进 Pd(II) 催化的通用和温和协议的开发,导致烯基和芳基硼化合物与各种烯烃的选择性交叉偶联。与大多数交叉偶联反应不同,这种新方法即使在没有碱基的情况下也能很好地工作,因此避免了不需要的同源偶联。包括二甲基菲咯啉在内的基于氮的配体增强了反应性,并提供了一种高效的立体选择性方法来克服具有挑战性的底物限制。例如,氧化钯 (II) 催化对于高度取代的烯烃和环烯烃是有效的,已知它们与其他已知的催化条件不相容。大多数检查的反应在低温和短时间内顺利完成。
An Efficient Approach to Chiral Allyloxyamines by Stereospecific Allylation of Nitrosoarenes with Chiral Allylboronates
作者:Yuanming Li、Shyamal Chakrabarty、Armido Studer
DOI:10.1002/anie.201410188
日期:2015.3.16
A novel and efficientapproach to allyloxyamines by the allylation of nitrosoarenes with α‐chiralallylboronates is described. CO bond formation occurs with high stereospecificity and the product allyloxyamines are easily transformed into valuable chiral building blocks such as isoxazolidines and allylic alcohols. The reaction features complete regioselectivity (O‐selectivity), high E/Z selectivity