Four copper(i) complexes, [CuBr(dtbpf)] (1), [CuI(dtbpf)] (2), [Cu4(μ2-I)2(μ3-I)2(μ-dtbpf)2] (3) and [Cu6(μ3-I)6(μ-dtbpf)2]·2CH3CN (4), were prepared using CuX (X = Br, I) and 1,1'-bis(di-tert-butylphosphino)ferrocene (dtbpf). These complexes have been characterized by elemental analyses, IR, (1)H and (31)P NMR, ESI-MS and electronic absorption spectroscopy. Molecular structures of the complexes 2 and 4 were determined crystallographically. Complex 2 is the first monomeric isolated Cu(i) complex of dtbpf with the largest P-Cu-P bite angle (120.070(19)°) to date. Complex 4 shows a centrosymmetrical dimeric unit with two [Cu3(μ3-I)3] motifs bridged by two bidentate dtbpf ligands in the κ(1)-manner. Each [Cu3(μ3-I)3] motif unites to form a pyramid with one copper atom at the apex and one of the triangular faces capped by an iodine atom. All the complexes were found to be efficient catalysts for the conversion of terminal alkynes into propiolic acids with CO2. Owing to the excellent catalytic activity, the reactions proceeded at atmospheric pressure and ambient temperature (25 °C). The catalytic products were obtained in moderate to good yields (80-96%) by using complex loading to 2 mol%. To the best of our knowledge, this is the first example of an active ferrocenyl diphosphine Cu(i) catalyst for the carboxylation of terminal alkynes with CO2.

Download full-text PDF

Source
http://dx.doi.org/10.1039/c5dt03794hDOI Listing

Publication Analysis

Top Keywords

terminal alkynes
12
carboxylation terminal
8
complex
5
11'-bisdi-tert-butylphosphinoferrocene copperi
4
copperi complex
4
complex catalyzed
4
catalyzed c-h
4
c-h activation
4
activation carboxylation
4
alkynes copperi
4

Similar Publications

Herein we report a cobalt-catalyzed hydroglycosylation of terminal alkynes, employing bench-stable ortho-iodobiphenyl (oIB) substituted sulfides as glycosyl donors. This reaction occurs with high stereo- and regioselectivity to afford E-configured vinyl α-C-glycosides, a class of compounds nontrivial to access by previous methods. The use of a bis(oxazoline) ligand with bulky side chains is critical for the high selectivities observed.

View Article and Find Full Text PDF

The group 1 alumanyls, [{SiN}AlM] (M = K, Rb, Cs; SiN = {CHSiMeNDipp}), display a variable kinetic facility (K < Rb < Cs) toward oxidative addition of the acidic C-H bond of terminal alkynes to provide the corresponding alkali metal hydrido(alkynyl)aluminate derivatives. Theoretical analysis of the formation of these compounds through density functional theory (DFT) calculations implies that the experimentally observed changes in reaction rate are a consequence of the variable stability of the [{SiN}AlM] dimers, the integrity of which reflects the ability of M to maintain the polyhapto group 1-arene interactions necessary for dimer propagation. These observations highlight that such "on-dimer" reactivity takes place sequentially and also that the ability of each constituent Al(I) center to effect the activation of the organic substrate is kinetically differentiated.

View Article and Find Full Text PDF

Secondary Alkylation of Arenes via the Borono-Catellani Strategy.

J Am Chem Soc

January 2025

Engineering Research Center of Organosilicon Compounds & Materials (Ministry of Education), Hubei Key Lab on Organic and Polymeric OptoElectronic Materials, College of Chemistry and Molecular Sciences, and TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan 430072, China.

A modular platform technology for the synthesis of α-aryl carbonyl derivatives via Borono-Catellani-type secondary alkylation of arenes is presented. This practical method features a broad substrate scope regarding aryl boronic acid catechol esters, secondary alkyl bromides, and diversified terminating reagents (e.g.

View Article and Find Full Text PDF

Zero-Valent Copper Catalysis Enables Regio- and Stereoselective Difunctionalization of Alkynes.

Angew Chem Int Ed Engl

January 2025

Jain University - Ramanagara Campus, Centre for Nano and Material Sciences, Jakkasandra Post Kanakapura Taluk, Ramanagara-562112, Bangalore, 562112, Bangalore, INDIA.

The development of a metallic copper-based catalyst system remains a significant challenge. Herein, we report the synthesis of highly stable, active, and reusable Cu0 catalyst for the carboboration of alkynes using carbon electrophiles and bis(pinacolato)diboron (B2pin2) as chemical feedstocks to afford di- and trisubstituted vinylboronate esters in a regio- and stereoselective manner with appreciable turnover number (TON) of up to 2535 under mild reaction conditions. This three-component coupling reaction works well with a variety of substituted electrophiles and alkynes with broad functional group tolerance.

View Article and Find Full Text PDF

From Pseudocyclic to Macrocyclic Ionophores: Strategies toward the Synthesis of Cyclic Monensin Derivatives.

J Org Chem

January 2025

Department of Medical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.

There has been a long search for a simple preparation of new cyclic analogues of ionophore antibiotics. We report a simple and general synthesis of three new cyclic derivatives of polyether ionophore, monensin A (MON). The application of the Huisgen 1,3-dipolar cycloaddition of azides and terminal alkynes to macrocyclization results in a concise, synthetic route to monensin lacton or lactam in only 4 steps.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!