1283231-74-2Relevant academic research and scientific papers
Synthesis of Alkenylboronates from N-Tosylhydrazones through Palladium-Catalyzed Carbene Migratory Insertion
Chang, Taiwei,Huo, Jingfeng,Lei, Ming,Ping, Yifan,Wang, Jianbo,Wang, Qianyue,Wang, Rui
supporting information, p. 9769 - 9780 (2021/07/19)
The palladium-catalyzed oxidative borylation reaction of N-tosylhydrazones has been developed. The reaction features mild conditions, broad substrate scope, and good functional group tolerance. It thus represents a highly efficient and practical method for the synthesis of di-, tri-, and tetrasubstituted alkenylboronates from readily available N-tosylhydrazones. One-pot Suzuki coupling and other transformations highlight the synthetic utility of the approach. DFT calculations have revealed that palladium-carbene formation and subsequent boryl migratory insertion are the key steps in the catalytic cycle. The high stereoselectivity observed in the formation of trisubstituted alkenylboronates has been explained by distortion-interaction analysis and NBO analysis.
Atroposelective Synthesis of Conjugated Diene-Based Axially Chiral Styrenes via Pd(II)-Catalyzed Thioether-Directed Alkenyl C-H Olefination
Jin, Liang,Zhang, Peng,Li, Ya,Yu, Xin,Shi, Bing-Feng
supporting information, p. 12335 - 12344 (2021/08/24)
The efficient stereoselective synthesis of conjugated dienes, especially those with axial chirality, remains a great challenge. Herein, we report the highly atroposelective synthesis of axially chiral styrenes with a conjugated 1,3-diene scaffold via a Pd(II)-catalyzed thioether-directed alkenyl C-H olefination strategy. This strategy features easy operation, mild reaction conditions, high functional group tolerance (69 examples), complete Z-selectivity, and excellent enantioselectivities (up to 99% ee). Notably, the highly enantioselective synthesis of atropisomers with two stereogenic axes were also achieved using this strategy (up to 99% ee and 97:3 dr). Moreover, the reaction could be scaled up, and the resulting axially chiral styrenes could be easily oxidized into chiral sulfoxide derivatives with high diastereoselectivities, which showed great promise as a new type of sulfur-olefin ligand.
Alkenyl boron compound and preparation method and application thereof
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Paragraph 0049-0052, (2020/12/14)
The invention discloses an alkenyl boron compound and a preparation method and application thereof. The preparation method comprises the following steps: in a protective atmosphere, enabling a uniformly mixed reaction system containing a lithium enol reag
Ru-catalyzed isomerization of ω-alkenylboronates towards stereoselective synthesis of vinylboronates with subsequent: In situ functionalization
Ho, Guo-Ming,Marek, Ilan,Segura, Lucas
, p. 5944 - 5949 (2020/07/10)
The stereoselective preparation of synthetically versatile vinylboronates from ω-alkenylboronates is achieved through a ruthenium-catalyzed isomerization reaction. A variety of di- A nd trisubstituted vinylboronates were conveniently produced and could be
Stereoselective Synthesis of Trisubstituted Vinylboronates from Ketone Enolates Triggered by 1,3-Metalate Rearrangement of Lithium Enolates
Hu, Yue,Sun, Wei,Zhang, Tao,Xu, Nuo,Xu, Jianeng,Lan, Yu,Liu, Chao
supporting information, p. 15813 - 15818 (2019/10/28)
An unprecedented stereoselective synthesis of trisubstituted vinylboronates is reported to proceed by direct borylation of lithium ketone enolates under transition-metal-free conditions. The stereospecific C?O borylation of lithium enolates was triggered by a carbonyl-induced 1,3-metalate rearrangement via a C-bound boron enolate. DFT calculations and control experiments revealed that the stereoselectivity is controlled by sterics. A variety of stereospecific trisubstituted vinylboronates, together with several tetrasubstituted vinylboronates, were conveniently synthesized with the newly developed methodology. Based on the transformation of stereospecific vinylboronate, a single isomer of Dienestrol was efficiently obtained.
Cyclodextrin Cavity-Induced Mechanistic Switch in Copper-Catalyzed Hydroboration
Zhang, Pinglu,Meijide Suárez, Jorge,Driant, Thomas,Derat, Etienne,Zhang, Yongmin,Ménand, Micka?l,Roland, Sylvain,Sollogoub, Matthieu
supporting information, p. 10821 - 10825 (2017/08/30)
N-heterocyclic carbene-capped cyclodextrin (ICyD) ligands, α-ICyD and β-ICyD derived from α- and β-cyclodextrin, respectively give opposite regioselectivities in a copper-catalyzed hydroboration. The site-selectivity results from two different mechanisms: the conventional parallel one and a new orthogonal mechanism. The shape of the cavity was shown not only to induce a regioselectivity switch but also a mechanistic switch. The scope of interest of the encapsulation of a reactive center is therefore broadened by this study.
Iron-Catalyzed Hydroboration: Unlocking Reactivity through Ligand Modulation
Espinal-Viguri, Maialen,Woof, Callum R.,Webster, Ruth L.
supporting information, p. 11605 - 11608 (2016/08/05)
Iron-catalyzed hydroboration (HB) of alkenes and alkynes is reported. A simple change in ligand structure leads to an extensive change in catalyst activity. Reactions proceed efficiently over a wide range of challenging substrates including activated, unactivated and sterically encumbered motifs. Conditions are mild and do not require the use of reducing agents or other additives. Large excesses of borating reagent are not required, allowing control of chemo- and regioselectivity in the presence of multiple double bonds. Mechanistic insight reveals that the reaction is likely to proceed via a highly reactive iron hydride intermediate.
Highly regio- and stereoselective synthesis of alkenylboronic esters by copper-catalyzed boron additions to disubstituted alkynes
Kim, Hye Ryung,Yun, Jaesook
, p. 2943 - 2945 (2011/05/04)
The copper-catalyzed addition of bis(pinacolato)diboron to internal alkynes in the presence of methanol generates alkenylboron compounds with high levels of regio- and stereoselectivities. The catalytic efficiency is increased by using monodentate phosphine ligands, especially P(p-tolyl)3 and a range of internal alkynes was borylated in good yields. The Royal Society of Chemistry.
