78782-17-9Relevant academic research and scientific papers
Catalytic borylation of methane
Smith, Kyle T.,Berritt, Simon,González-Moreiras, Mariano,Ahn, Seihwan,Smith, Milton R.,Baik, Mu-Hyun,Mindiola, Daniel J.
, p. 1424 - 1427 (2016)
Despite steady progress in catalytic methods for the borylation of hydrocarbons, methane has not yet been subject to this transformation. Here we report the iridium-catalyzed borylation of methane using bis(pinacolborane) in cyclohexane solvent. Initially, trace amounts of borylated products were detected with phenanthroline-coordinated Ir complexes. A combination of experimental high-pressure and high-throughput screening, and computational mechanism discovery techniques helped to rationalize the foundation of the catalysis and identify improved phosphine-coordinated catalytic complexes. Optimized conditions of 150°C and 3500-kilopascal pressure led to yields as high as ～52%, turnover numbers of 100, and improved chemoselectivity for monoborylated versus diborylated methane.
Rhodium-catalyzed borylative carbon monoxide reduction to gem-diborylmethane
Wu, Fu-Peng,Wu, Xiao-Feng,Xu, Jian-Xing
, (2021)
Herein, we developed a rhodium-catalyzed reduction of CO with bis(pinacolato)diboron (B2pin2) under atmospheric pressure of CO with silane as the hydride source, gem-diborylmethane [H2C(Bpin)2] as a versatile and fundamental C1 compound can be formed. Notably, this is the first example on transition metal-catalyzed borylation of CO.
An Olefinic 1,2-α-Boryl Migration Enables 1,2-Bis(boronic esters) via Radical-Polar Crossover Reaction
Zhang, Feng,Liao, Shangteng,Zhou, Lu,Yang, Kai,Wang, Chenglan,Lou, Yixian,Wang, Cece,Song, Qiuling
supporting information, p. 582 - 588 (2022/01/11)
A radical-induced 1,2-α-boryl migration through radical polar crossover reactions has been described. In this work, in situ formed vinyldiboron “ate” complexes from alkenyl Grignard reagent and diborylalkanes react with commercial radical precursors under light initiation. This three-component process enables diborylation of alkene. This protocol features high atom economy, a broad substrate scope as well as good functional group toleration with mild conditions.
A site-selective and stereospecific cascade Suzuki-Miyaura annulation of alkyl 1,2-bisboronic esters and 2,2′-dihalo 1,1′-biaryls
Willems, Suzanne,Toupalas, Georgios,Reisenbauer, Julia C.,Morandi, Bill
supporting information, p. 3909 - 3912 (2021/04/26)
A cascade Suzuki-Miyaura cross-coupling giving rise to 9,10-dihydrophenanthrenes has been developed. Using biaryls with unsymmetrical substitution-pattern full site-selectivity was observed. Furthermore, this cross-coupling of an alkyl 1,2-bisboronic pinacol ester proceeds through the challenging coupling of a secondary boronate with complete stereoretention.
Synthesis of a Biomimetic Tetracyclic Precursor of Aspochalasins and Formal Synthesis of Trichoderone A
Gayraud, Oscar,Laroche, Benjamin,Casaretto, Nicolas,Nay, Bastien
supporting information, p. 5755 - 5760 (2021/08/16)
Aspochalasins are leucine-derived cytochalasins. Their complexity is associated with a high degree of biosynthetic oxidation, herein inspiring a two-phase strategy in total synthesis. We thus describe the synthesis of a putative biomimetic tetracyclic int
Conformationally Controlled Linear and Helical Hydrocarbons Bearing Extended Side Chains
Aggarwal, Varinder K.,Butts, Craig P.,Davy, Matthew,Dutton, Oliver J.,Guo, Lin,Kucukdisli, Murat,Myers, Eddie L.,Wagnières, Olivier
supporting information, p. 16682 - 16692 (2021/10/21)
Conformationally controlled flexible molecules are ideal for applications in medicine and materials, where shape matters but an ability to adapt to multiple and changing environments is often required. The conformation of flexible hydrocarbon chains bearing contiguous methyl substituents is controlled through the avoidance of syn-pentane interactions: alternating syn-anti isomers adopt a linear conformation while all-syn isomers adopt a helical conformation. From a simple diamond lattice analysis, larger substituents, which would be required for most potential applications, result in significant and unavoidable syn-pentane interactions, suggesting substantially reduced conformational control. Through a combination of computation, synthesis, and NMR analysis, we have identified a selection of substitution patterns that allow large groups to be incorporated on conformationally controlled linear and helical hydrocarbon chains. Surprisingly, when the methyl substituents of alternating syn-anti hydrocarbons are replaced with acetoxyethyl groups, the main chain of almost 95% of the population of molecules adopt a linear conformation. Here, the side chains adopt nonideal eclipsed conformations with the main chain, thus minimizing syn-pentane interactions. In the case of all-syn hydrocarbons, concurrent removal of some methyl groups on the main chain adjacent to the large substituents is required to maintain a high population of molecules adopting a helical conformation. This information can now be used to design flexible hydrocarbon chains displaying functional groups in a defined relative orientation for multivalent binding or cooperative reactivity, for example, in targeting the interfaces defined by disease-relevant protein-protein interactions.
Efficient synthesis of alkylboronic esters: Via magnetically recoverable copper nanoparticle-catalyzed borylation of alkyl chlorides and bromides
Shegavi, Mahadev L.,Agarwal, Abhishek,Bose, Shubhankar Kumar
supporting information, p. 2799 - 2803 (2020/06/17)
We report a magnetically separable Cu nanocatalyst (Fe-DOPA-Cu) for the borylation of alkyl halides with alkoxy diboron reagents, providing alkylboronic esters in high yields, with broad functional group tolerance under mild reaction conditions. The procedure is also applicable to the borylation of benzyl chlorides and bromides. Radical clock experiments support a radical-mediated process. Easy recycling of the catalyst resulted in no significant loss of activity up to ten runs.
Efficient and Selective Methane Borylation Through Pore Size Tuning of Hybrid Porous Organic-Polymer-Based Iridium Catalysts
Chen, Qi,Dong, Anwang,Wang, Dongxu,Qiu, Lu,Ma, Chunxin,Yuan, Yihui,Zhao, Yunpeng,Jia, Na,Guo, Zhanhu,Wang, Ning
supporting information, p. 10671 - 10676 (2019/07/04)
As a new energy source that could replace petroleum, the global reserves of methane hydrate (combustible ice) are estimated to be approximately 20 000 trillion cubic meters. A large amount of methane hydrate has been found under the seabed, but the transportation and storage of methane gas far from coastlines are technically unfeasible and expensive. The direct conversion of methane into value-added chemicals and liquid fuels is highly desirable but remains challenging. Herein, we prepare a series of iridium complexes based on porous polycarbazoles with high specific areas and good thermochemical stabilities. Through structure tuning we optimized their catalytic activities for the selective monoborylation of methane. One of these catalysts (CAL-3-Ir) can produce methyl boronic acid pinacol ester (CH3Bpin) in 29 % yield in 9 h with a turnover frequency (TOF) of approximately 14 h?1. Because its pore sizes favor monoborylated products, it has a high chemoselectivity for monoborylation (CH3Bpin:CH2(Bpin)2=16:1).
C-O Functionalization of α-Oxyboronates: A Deoxygenative gem-Diborylation and gem-Silylborylation of Aldehydes and Ketones
Wang, Lu,Zhang, Tao,Sun, Wei,He, Zeyu,Xia, Chungu,Lan, Yu,Liu, Chao
supporting information, p. 5257 - 5264 (2017/05/04)
A deoxygenative gem-diborylation and gem-silylborylation of aldehydes and ketones is described. The key for the success of this transformation is the base-promoted C-O bond borylation or silylation of the generated α-oxyboronates. Experimental and theoret
A Boron Alkylidene–Alkene Cycloaddition Reaction: Application to the Synthesis of Aphanamal
Liu, Xun,Deaton, T. Maxwell,Haeffner, Fredrik,Morken, James P.
supporting information, p. 11485 - 11489 (2017/09/11)
We describe an unusual net [2+2] cycloaddition reaction between boron alkylidenes and unactivated alkenes. This reaction provides a new method for the construction of carbocyclic ring systems bearing versatile organoboronic esters. Aside from surveying the scope of this reaction, we provide details about the mechanistic underpinnings of this process, and examine its application to the synthesis of the natural product aphanamal.
