1184-55-0Relevant academic research and scientific papers
Synthesis and characterisation of trigonal C2-chiral di- and tetra-substituted bis(oxazoline) alkyl zinc complexes and their reactivity towards protic reagents
Le Roux, Erwan,Merle, Nicolas,Toernroos, Karl W.
, p. 1768 - 1777 (2011)
A series of zinc(ii) alkyl complexes stabilised by the C2-chiral bis(oxazoline) ligand (R1,R2BOX, with R1 = (4S)-tBu, R2 = H (a); R1 = (4S)-Ph, R2 = H (b); R1 = (4R)-Ph, R2 = (5S)-Ph (c)), has been synthesised and structurally characterised. (R1,R2BOX)H ligands react with ZnEt2 in toluene to give the heteroleptic three-coordinate compounds of (R1,R2BOX)ZnEt, 1a, 1b and 1c in high yield. However, when the addition of (BOX)H ligands (a-b) over ZnEt2 is "uncontrolled", the formation of homoleptic four-coordinate compounds are favoured (2a-b), but not for the more sterically crowded ligand (c). The zinc-ethyl derivatives (1a-c) react readily with protic reagents such as acetic acid (HOAc) and methanol (MeOH). For compounds 1a-c a redistribution of ligands is observed leading preferentially to homoleptic compounds, except for the bulkier ligand c providing a three-coordinate complex identified as ( Ph,PhBOX)Zn(OMe), 4c. The reaction of acetylacetone (acacH) with compounds 1a-c leads straightforwardly to the more stable four-coordinate compounds corresponding to (R1,R2BOX)Zn(η2- acac), 5a-c. The potential of these compounds as initiators for the copolymerisation of epoxides with CO2 was investigated.
The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)-O Arylation
Mills, L. Reginald,Monteith, John J.,Dos Passos Gomes, Gabriel,Aspuru-Guzik, Alán,Rousseaux, Sophie A. L.
supporting information, p. 13246 - 13254 (2020/09/01)
The ability to understand and predict reactivity is essential for the development of new reactions. In the context of Ni-catalyzed C(sp3)-O functionalization, we have developed a unique strategy employing activated cyclopropanols to aid the design and optimization of a redox-active leaving group for C(sp3)-O arylation. In this chemistry, the cyclopropane ring acts as a reporter of leaving-group reactivity, since the ring-opened product is obtained under polar (2e) conditions, and the ring-closed product is obtained under radical (1e) conditions. Mechanistic studies demonstrate that the optimal leaving group is redox-active and are consistent with a Ni(I)/Ni(III) catalytic cycle. The optimized reaction conditions are also used to synthesize a number of arylcyclopropanes, which are valuable pharmaceutical motifs.
Electrochemical reactions at sacrificial electrodes: Synthesis of zinc(II) alkoxides. Part XVII
Banait,Singh, Baljit,Kaur, Harpreet
, p. 266 - 268 (2008/02/08)
Electrochemical reactions of various alcohols have been carried out at sacrificial zinc anode and inert platinum cathode using tetrabutylammonium chloride as supporting electrolyte and acetonitrile as solvent. Solid products obtained from the anode compartment have been identified as zinc(II) alkoxides by elemental analysis and infrared spectral data. The current efficiencies of these systems have been found to be very high.
Structure and reactivity of mono- and dinuclear diiminate zinc alkyl complexes
Allen, Scott D.,Moore, David R.,Lobkovsky, Emil B.,Coates, Geoffrey W.
, p. 137 - 148 (2007/10/03)
The synthesis, structure and reactivity of several diiminate ligands are presented. The syntheses of five representative β-diiminate (BDI) zinc alkyl complexes and one β-oxo-δ-diiminate (BODDI) zinc alkyl are described. BDI ligands with varying backbone and N -aryl substituents display different solid state structures. [(BDI)ZnR] are synthesized by the reaction of (BDI)H with ZnR2 in quantitative yield. Previously reported (BDI-1)ZnEt is a three-coordinate monomer in the solid state whereas [(BDI-3)ZnEt]∞ [(BDI-3)=2-((2,6-diisopropylphenyl) amido)-3-cyano-4-((2,6-diisopropylphenyl)imino-2-pentene] and [(BDI-4) ZnEt]∞ [(BDI-4)=2-((2,6-diethylphenyl)amido)-3-cyano-4- ((2,6-diethylphenyl)imino-2-pentene] form one dimensional coordination polymers. The bimetallic complex [(BODDI-1)(ZnEt)2] [(BODDI-1)=2,6-bis((2,6-diisopropylphenyl)amido)-2,5-heptadien-4-one] is prepared through the reaction of (BODDI-1)H2 with two equivalents ZnEt2. Both [(BDI)ZnEt] and [(BODDI)ZnEt] complexes react with acetic acid to give the acetate complexes in moderate to high yields, offering a superior synthetic route to these complexes. [(BDI)ZnR] [BDI=(BDI-3) or 1,1,1-trifluoro-2- ((2,6-diisopropylphenyl) amido)-4-((2,6-diethylphenyl)imino-2-pentene), (BDI-5)] complexes react with MeOH to produce [{(BDI)Zn(μ-OMe)} 2Zn(μ-OMe) 2] in moderate yields. The molecular structures of [(BDI-3)ZnEt], [(BDI-4)ZnEt], [(BODDI-1)(ZnEt) 2], [(BODDI-1) Zn2(μ-OAc)2], [{(BDI-3)Zn(μ-OMe)}2 Zn(μ-OMe)2] and [{(BDI-5)Zn(μ-OMe)}2 Zn(μ-OMe)2] have been determined by X-ray diffraction.
