13122-34-4Relevant articles and documents
Facile H/D exchange at (hetero)aromatic hydrocarbons catalyzed by a stable trans-dihydride n-heterocyclic carbene (NHC) iron complex
De Ruiter, Graham,Garhwal, Subhash,Kaushansky, Alexander,Fridman, Natalia,Shimon, Linda J.W.
, p. 17131 - 17139 (2020)
Earth-abundant metal pincer complexes have played an important role in homogeneous catalysis during the last ten years. Yet, despite intense research efforts, the synthesis of iron PCcarbeneP pincer complexes has so far remained elusive. Here we report the synthesis of the first PCNHCP functionalized iron complex [(PCNHCP)FeCl2] (1) and the reactivity of the corresponding trans-dihydride iron(II) dinitrogen complex [(PCNHCP)- Fe(H)2N2)] (2). Complex 2 is stable under an atmosphere of N2 and is highly active for hydrogen isotope exchange at (hetero)aromatic hydrocarbons under mild conditions (50 °C, N2). With benzene-d6 as the deuterium source, easily reducible functional groups such as esters and amides are well tolerated, contributing to the overall wide substrate scope (e.g., halides, ethers, and amines). DFT studies suggest a complex assisted σ-bond metathesis pathway for C(sp2)-H bond activation, which is further discussed in this study.
Photoinduced catalyst-free deborylation-deuteration of arylboronic acids with D2O
Lang, Yatao,Li, Chao-Jun,Peng, Xiangjun,Zeng, Huiying
supporting information, p. 6323 - 6327 (2020/11/09)
Herein, novel photoinduced catalyst-free deborylation-deuteration of arylboronic acids with D2O is reported. The protocol was compatible with a variety of functionalities, including halogen, alkoxy, cyano, sulfonyl, trimethylsilyl, trifluoromethoxy, alkyl, hydroxyl, free acid, amide, and heteroaromatic rings. A wide range of deuterated products were obtained in good yields with a high level of deuteration. This method provides a green and practical pathway to synthesize deuterium labelled compounds under mild conditions.
Electrocatalytic Deuteration of Halides with D2O as the Deuterium Source over a Copper Nanowire Arrays Cathode
Chong, Xiaodan,Han, Shuyan,Li, Mengyang,Liu, Cuibo,Zhang, Bin
supporting information, p. 18527 - 18531 (2020/08/21)
Precise deuterium incorporation with controllable deuterated sites is extremely desirable. Here, a facile and efficient electrocatalytic deuterodehalogenation of halides using D2O as the deuteration reagent and copper nanowire arrays (Cu NWAs) electrochemically formed in situ as the cathode was demonstrated. A cross-coupling of carbon and deuterium free radicals might be involved for this ipso-selective deuteration. This method exhibited excellent chemoselectivity and high compatibility with the easily reducible functional groups (C=C, C≡C, C=O, C=N, C≡N). The C?H to C?D transformations were achieved with high yields and deuterium ratios through a one-pot halogenation–deuterodehalogenation process. Efficient deuteration of less-active bromide substrates, specific deuterium incorporation into top-selling pharmaceuticals, and oxidant-free paired anodic synthesis of high-value chemicals with low energy input highlighted the potential practicality.
Hydro/deutero deamination of arylazo sulfones under metal and (photo)catalyst-free conditions
Amin, Hawraz I.M.,Raviola, Carlotta,Amin, Ahmed A.,Mannucci, Barbara,Protti, Stefano,Fagnoni, Maurizio
, (2019/06/19)
Hydrodeaminated and monodeuterated aromatics were obtained via a visible-light driven reaction of arylazo sulfones. Deuteration occurs efficiently in deuterated media such as isopropanol-d8 or in THF-d8/water mixtures and exhibits a high tolerance to the nature and the position of the aromatic substituents.
Metal-Free sp2-C-H Borylation as a Common Reactivity Pattern of Frustrated 2-Aminophenylboranes
Chernichenko, Konstantin,Lindqvist, Markus,Kótai, Bianka,Nieger, Martin,Sorochkina, Kristina,Pápai, Imre,Repo, Timo
supporting information, p. 4860 - 4868 (2016/05/10)
C-H borylation is a powerful and atom-efficient method for converting affordable and abundant chemicals into versatile organic reagents used in the production of fine chemicals and functional materials. Herein we report a facile C-H borylation of aromatic and olefinic C-H bonds with 2-aminophenylboranes. Computational and experimental studies reveal that the metal-free C-H insertion proceeds via a frustrated Lewis pair mechanism involving heterolytic splitting of the C-H bond by cooperative action of the amine and boryl groups. The adapted geometry of the reactive B and N centers results in an unprecedentently low kinetic barrier for both insertion into the sp2-C-H bond and intramolecular protonation of the sp2-C-B bond in 2-ammoniophenyl(aryl)- or -(alkenyl)borates. This common reactivity pattern serves as a platform for various catalytic reactions such as C-H borylation and hydrogenation of alkynes. In particular, we demonstrate that simple 2-aminopyridinium salts efficiently catalyze the C-H borylation of hetarenes with catecholborane. This reaction is presumably mediated by a borenium species isoelectronic to 2-aminophenylboranes.
Borohydride exchange resin as an alternative method for deuterium labelling: selective reduction of aryl bromides
Landvatter, Scott W.,Schauer, Douglas J.,Garnes, Keith T.,Mack, James F.,Killmer, Lewis B.
, p. 1025 - 1034 (2007/10/03)
Transition metal-activated borohydride exchange resin and borodeuteride exchange resin have been prepared and used for the selective reductive deuteration of aryl bromides. This methodology, which utilizes deuterated methanol as the primary source of labe
Titanium Catalyzed Reduction of Aromatic Halides by Sodium Borohydride
Liu, Yumin,Schwartz, Jeffrey
, p. 4471 - 4482 (2007/10/02)
The reduction of aryl halides by sodium borohydride is catalyzed by titanium complexes; di(cyclopentadienyl)titanium dichloride (titanocence dichloride) is highly effective.The reaction scope and mechanism are solvent dependent.In dimethylformamide (DMF), an adduct of DMF and sodium borohydride is formed which reduces simple aryl halides by a non-radical, likely nucleophilic route.Dimethylamino- substituted products are formed, as are simple dechlorinated species.In dimethylacetamide or in ethers, a radical-based reaction involving activated titanocene borohydride takes place, and only dechlorinated products result.
The Mechanism of Titanium Complex-Catalyzed Reduction of Aryl Halides by Sodium Borohydride Is Strongly Solvent Dependent
Liu, Yumin,Schwartz, Jeffrey
, p. 940 - 942 (2007/10/02)
The titanium complex-catalyzed reduction of aryl halides by sodium borohydride in dimethylacetamide (DMA) or ethers proceeds by electron transfer from a reduced titanium species, yielding an intermediate aryl radical.
Gas-phase oxygenation of benzene derivatives around 300 K with O(3P) atoms produced by microwave discharge of N2O. Part 2. Kinetic H/D isotope effects.
Sol, Veronica M.,Louw, Robert,Mulder, Peter
, p. 346 - 352 (2007/10/02)
The possible pathways for the formation of (chloro)phenol, following the addition of O(3P) to (chloro)benzene, have been examined using deuterated substrates: C6D6 (also in admixture with C6H6) and p-deuterochlorobenzene.Whereas with O-C6H6 adduct biradicals, loss of H* to give phenoxy radicals predominates, only one-third of the O-C5D6 intermediates undergo the corresponding reaction.Phenoxy radicals lead to phenol by transfer of an H(D) atom from cyclohexadienyl-type radicals, formed from H* (D*) and substrate.Analogously, in reactions of p-deuterochlorobenzene, loss of H is a major reaction after addition of an oxygen atom to a meta position, whereas loss of D (to give p-chlorophenol) occurs only with 35percent of the corresponding O(3P) adduct biradicals.The isotopic composition of phenol formed from p-DC6H4Cl (via p-DC6H4O*; generated by ipso substitution) revealed that H transfer to phenoxy radicals primarily gives the keto tautomers as major products.Isomerization of (chloro)benzene-O(3P) adduct biradicals to the corresponding phenols also appears to involve mainly, keto tautomers.The reaction of O(3P) with p-deuterochlorobenzene showed a slight change in the o/m/p distribution; this can be explained by the absence of a net secondary H/D isotope effect for O(3P) addition to the para site and a normal secondary isotope effect for meta addition.
