173603-23-1Relevant academic research and scientific papers
Atomic-dispersed platinum anchored on porous alumina sheets as an efficient catalyst for diboration of alkynes
Chen, Wenxing,Jiang, Zhuoli,Shang, Huishan,Zhang, Jiatao,Zhou, Danni
, p. 3127 - 3130 (2020)
Atomic-dispersed Pt anchored on defect-rich porous alumina sheets (Pt/dp-Al2O3) was accessed via a wet impregnation combined with pyrolysis method. These nanosheets functionalized by atomic-dispersed Pt possess a high density of active sites, exhibiting an exceptional catalytic activity combined with cyclic performance in the diboration of alkynes. The selectivity and conversion yield could reach as high as 97% and 98%, respectively.
A general strategy to prepare atomically dispersed biomimetic catalysts based on host-guest chemistry
Han, Xiao,Chen, Zheng,Chen, Wenxing,Lv, Chunlin,Ji, Yongjun,Li, Jing,Cheong, Weng-Chon,Lei, Xiaojuan,Peng, Qing,Chen, Chen,Wang, Dingsheng,Lian, Chao,Li, Yadong
supporting information, p. 1895 - 1898 (2021/03/01)
Herein, we report a general strategy based on host-guest interactions to fabricate atomically dispersed biomimetic catalysts, which were evaluated by diboration of phenylacetylene. The structure and function of these mimics are quite similar to those of enzymes, namely, the atomically dispersed metal serves as an active site, the external macromolecular structure plays a role as an enzyme catalytic pocket to stabilize the reaction intermediates and the interactions between the intermediates and functional groups near to the active site can reduce the reaction activation energy.
Dehydrogenative Diboration of Alkynes Catalyzed by Ir/CO/tBuNC System
Lai, Qingheng,Ozerov, Oleg V.
, (2020/11/30)
Catalytic dehydrogenative diboration (DHDB) of alkyne with HBpin was achieved using [Ir(COD)Cl]2 and other related Ir precursors under CO atmosphere. The selectivity for DHDB over hydroboration was higher in less polar solvents and under higher
Base-catalyzed diborylation of alkynes: synthesis and applications of cis-1,2-bis(boryl)alkenes
Kuang, Zhijie,Gao, Guoliang,Song, Qiuling
, p. 62 - 66 (2018/09/27)
An efficient, transition-metal free, and practical approach to cis-bis(boryl)alkenes from various alkynes was disclosed in the presence of a catalytic amount of K2CO3 under mild conditions. Meanwhile, tetrasubstituted alkenes and phenanthrene derivatives were readily constructed from the target diborylalkenes via Suzuki-Miyaura cross coupling.
Gold-nanoparticle-catalyzed mild diboration and indirect silaboration of alkynes without the use of silylboranes
Kidonakis, Marios,Stratakis, Manolis
, p. 4265 - 4271 (2017/11/09)
Commercially available Au nanoparticles supported on TiO2 were used to catalyze the cis diboration of terminal and internal alkynes with bis(pinacolato)diboron. The products were obtained in excellent yields by using milder conditions, shorter reaction times, and lower catalyst loadings than those required for a heterogeneous Au nanopore catalyst. The catalytic system could be recovered and reused for five consecutive runs without any loss of activity. The combination of bis(pinacolato)- diboron with the 1,2-disilane in the presence of Au/TiO2 allowed for the σ-bond metathesis to take place and the in situ formation of the Au nanoparticle-tethered silylborane. Given that the Au-catalyzed silaboration of alkynes is faster than the rates of the corresponding disilylation and diboration pathways, we were able to achieve the indirect silaboration of alkynes with good chemoselectivities (65–85 %) without the direct use of silylboranes, which are expensive and difficult to synthesize.
An experimental and theoretical study into the facile, homogenous (N-heterocyclic carbene)2-Pd(0) catalyzed diboration of internal and terminal alkynes
Ansell, Melvyn B.,Menezes Da Silva, Vitor H.,Heerdt, Gabriel,Braga, Ataualpa A. C.,Spencer, John,Navarro, Oscar
, p. 7461 - 7467 (2016/10/21)
Pd(ITMe)2(PhCCPh) acts as a highly reactive pre-catalyst in the unprecedented homogenous catalyzed diboration of terminal and internal alkynes, yielding a number of novel and known syn-1,2-diborylalkenes in a 100% stereoselective manner. DFT calculations suggest that a similar reaction pathway to that proposed for platinum phosphine analogues is followed, and that destabilization of key intermediates by the NHCs is vital to the overall success for the palladium-catalyzed B-B addition to alkynes.
Solvent-and ligand-free diboration of alkynes and alkenes catalyzed by platinum nanoparticles on titania
Alonso, Francisco,Moglie, Yanina,Pastor-Perez, Laura,Sepulveda-Escribano, Antonio
, p. 857 - 865 (2014/03/21)
Platinum nanoparticles supported on titania efficiently catalyzed the diboration of alkynes and alkenes under solvent-and ligand-free conditions in air. The cis-1,2-diborylalkenes and 1,2-diborylalkanes were obtained in moderate to excellent yields following, in most cases, a simple filtration workup protocol. The versatility of the cis-1,2-diboronvinyl compounds was demonstrated in a series of organic transformations, including the Suzuki-Miyaura cross coupling and the boron-halogen exchange. Click diboration: The diboration of alkynes and alkenes catalyzed by platinum nanoparticles on titania is shown to take place under solvent-and ligand-free conditions in air. The 1,2-diboronvinyl compounds are obtained with exclusive cis stereochemistry and are subjected to different useful chemical transformations.
Remarkable catalytic property of nanoporous gold on activation of diborons for direct diboration of alkynes
Chen, Qiang,Zhao, Jian,Ishikawa, Yoshifumi,Asao, Naoki,Yamamoto, Yoshinori,Jin, Tienan
supporting information, p. 5766 - 5769 (2013/12/04)
A novel catalytic property of nanoporous gold for activation of bis(pinacolato)diboron has been reported that allows the direct diboration of alkynes to proceed sufficiently in a heterogeneous process. The experimental results revealed that the nanoporous gold catalyst is able to cleave the B-B bond of bis(pinacolato)diboron without using any additives.
Stereoselective single (copper) or double (platinum) boronation of alkynes catalyzed by magnesia-supported copper oxide or platinum nanoparticles
Grirrane, Abdessamad,Corma, Avelino,Garcia, Hermenegildo
scheme or table, p. 2467 - 2478 (2011/04/24)
Copper(II) oxide nanoparticles supported on magnesia have been prepared from CuII supported on magnesia by hydrogen reduction at 400°C followed by storage under ambient conditions. X-ray photoelectron spectroscopy of the material clearly shows that immediately after the reduction copper(0)-metal nanoparticles are present on the magnesia support, but they undergo fast oxidation to copper oxide upon contact with the ambient for a short time. TEM images show that the catalytically active CuO/MgO material is formed of well-dispersed copper oxide nanoparticles supported on fibrous MgO. CuO/MgO exhibits a remarkable catalytic activity for the monoborylation of aromatic, aliphatic, terminal, and internal alkynes, the products being formed with high regio-(borylation at the less substituted carbon) and stereoselectivity (trans-configured). CuO/MgO exhibits complete chemoselectivity towards the monoborylation of alkynes in the presence of alkenes. Other metal nanoparticles such as gold or palladium are inactive towards borylation, but undergo undesirable oligomerization or partial hydrogenation of the Ci￡C triple bond. In contrast, platinum, either supported on magnesia or on nanoparticulate ceria, efficiently promotes the stereoselective diborylation of alkynes to yield a cis-configured diboronate alkene. By using platinum as the catalyst we have developed a tandem diborylation/hydrogenation reaction that gives vic-diboronated alkanes from alkynes in one pot.
One-pot synthesis of α,α-difluoroimines from alkynes through tandem catalytic diboration/fluorination/imination reaction
Ramírez, Jesús,Fernández, Elena
, p. 3841 - 3845 (2008/02/07)
Tandem catalytic diboration/fluorination/imination of arylacetylenes leads to the formation of α,α-difluoroimines, where the adjacent C{double bond, long}N and C-F2 bonds are formed simultaneously. The convenient one-pot protocol involves a Pt(0)-catalyzed diboration of terminal or internal arylalkynes followed by electrophilic fluorination with Selectfluor in the presence of primary amines and a dehydrating agent. A plausible mechanism for the three consecutive steps (diboration/fluorination/imination) is suggested in accordance with the electronic properties of the substrates. Alkynes/catalytic diboration/alkenyl diboronate esters/Selectfluor/electrophilic fluorination/α,α-difluoroimines.
