Ni(cod)2 / P(p -CF 3 C 6 H 4)3催化剂在室温下实现三异丙基甲硅烷基乙炔,二芳基乙炔和末端炔烃之间的高度化学,区域和立体选择性三组分交叉三聚反应通过末端甲硅烷基乙炔的选择性CH氧化加成反应达到最高温度。该反应适用于各种二芳基乙炔和末端炔烃,得到相应的1,3-二烯-5-炔化合物。
that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides, and redox-active N-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to an 89% yield as single regio- and E isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable
Reductive Decarboxylative Alkynylation of
<i>N</i>
‐Hydroxyphthalimide Esters with Bromoalkynes
作者:Liangbin Huang、Astrid M. Olivares、Daniel J. Weix
DOI:10.1002/anie.201706781
日期:2017.9.18
A new method for the synthesis of terminal and internal alkynes from the nickel‐catalyzed decarboxylative coupling of N‐hydroxyphthalimide esters and bromoalkynes is presented. This reductivecross‐electrophilecoupling is the first to use a C(sp)−X electrophile, and appears to proceed via an alkynylnickel intermediate. The internal alkyne products are obtained in yields of 41–95 % without the need
Ethynyl Benziodoxolones for the Direct Alkynylation of Heterocycles: Structural Requirement, Improved Procedure for Pyrroles, and Insights into the Mechanism
作者:Jonathan P. Brand、Clara Chevalley、Rosario Scopelliti、Jérôme Waser
DOI:10.1002/chem.201200200
日期:2012.4.27
accelerating effect of a methyl substituent in both the 3‐ and 6‐position of triisopropylsilylethynyl‐1,2‐benziodoxol‐3(1H)‐one (TIPS‐EBX) on the reaction rate was observed. Competitive experiments between substrates of different nucleophilicity, deuterium labeling experiments, as well as the regioselectivity observed are all in agreement with electrophilic aromatic substitution. Gold(III) 2‐pyridinecarboxylate
TBA = tetra-n-butylammonium) could act as an efficient reusable homogeneous catalyst for the aerobic oxidative alkyne homocoupling. Various kinds of structurally diverse terminalalkynes including aromatic, heteroaromatic, aliphatic, double bond-containing, silylacetylene, propargylicalcohol, and propargylic amine derivatives could selectively be converted into the corresponding diynes in the presence of I.
C(sp2)-C(sp) and C(sp)-C(sp) Coupling Reactions Catalyzed by Oxime-Derived Palladacycles
作者:Diego A. Alonso、Carmen Nájera、Ma Carmen Pacheco
DOI:10.1002/adsc.200303067
日期:2003.9
4′-dichlorobenzophenone, is an efficient pre-catalyst for the copper- and amine-free Sonogashira coupling between terminal acetylenes and aryl iodides and aryl and vinyl bromides achieving turnover numbers (TON) of up to 72000. Catalyst 8a has also been shown as a effective promoter for the sila-Sonogashira coupling between 1-(trimethylsilyl)alkynes and aryl iodides and bromides in the presence of CuI or