340-04-5Relevant articles and documents
Kinetic study on photocatalytic hydrogenation of acetophenone derivatives on titanium dioxide
Kohtani, Shigeru,Kamoi, Yuna,Yoshioka, Eito,Miyabe, Hideto
, p. 1084 - 1091 (2014)
Acetophenone (AP) derivatives were photocatalytically hydrogenated to afford the corresponding secondary alcohols with excellent chemical efficiencies on titanium dioxide (Degussa P25, TiO2) under UV light irradiation. Maximum reaction rates (kmax) and apparent adsorption constants (KLH) under irradiation were obtained from the Langmuir-Hinshelwood kinetic analysis. The kmax values showed a tendency to decrease with the decreasing reduction potentials (Ered) of the AP derivatives, while the KLH values were distributed in the range of 280-780 L mol-1. Among these, simple AP exhibited the greatest adsorptivity upon the UV irradiated TiO2 surface. Additionally, it was demonstrated that the electrons trapped at surface defect Ti (Tist) sites on the TiO2 actually hydrogenated the AP derivatives. The amount of reacted electrons also showed a tendency to decrease with decreasing Ered values, in accord with the dependence on kmax. These results indicate that the electrons accumulated at shallow Tist states easily participate in the hydrogenation of AP derivatives, whereas those trapped at deeper states hardly react with the substrates. The results strongly support the electron transfer reaction model via the Tist sites in the photocatalytic hydrogenation on TiO2. This journal is the Partner Organisations 2014.
Hemiaminals of trifluoroacetaldehyde, as trifluoromethylating agents
Mispelaere, Clotilde,Roques, Nicolas
, p. 6411 - 6414 (1999)
Hemiaminals of trifluoroacetaldehyde are new trifluoromethylating agents. These reagents are synthesised from amines and gaseous trifluoroacetaldehyde. tBuONa is able to deprotonate the hemiaminals to form trifluoromethyl anion equivalents CF3CH(O-)NMe2. The trifluoromethyl anion has been transferred from such intermediates to benzaldehyde yielding phenyl (trifluoromethyl) methanol.
Trifluoromethylketones chemistry: Efficient access to silyl enol ethers or silyl carbinols using lithium diisopropylamide
Provot, Olivier,Berrien, Jean-Francois,Moskowitz, Henri,Mayrargue, Joelle
, p. 185 - 187 (1997)
Lithium diisopropylamide, reacts with trifluoromethylketones either as a base in polar solvents or as a hydride donor in hexane. In the presence of terf-Butyldimethylsilyl chloride, Lithium diisopropylamide allows the transformation of trifluoromethylketo
TRIFLUOROMETHYLATION OF CARBONYL COMPOUNDS WITH TRIFLUOROMETHYLZINC IODIDE UNDER ULTRASONIC IRRADIATION
Kitazume, Tomoya,Ishikawa, Nobuo
, p. 1679 - 1680 (1981)
The trifluoromethylation of carbonyl compounds with trifluoromethylzinc iodide, prepared from trifluoromethyl iodide with ultrasonically dispersed zinc, smoothly proceeded to give corresponding α-trifluoromethyl carbinols in good yields.
1H, 13C, and 19F Nuclear Polarizations in the Photochemistry of α,α,α-Trifluoroacetophenone
Wagner, Peter J.,Thomas, Michael J.
, p. 4173 - 4182 (1980)
CIDNP effects are observed during irradiation of α,α,α-trifluoroacetophenone (TFA) and several of its ring-substituted derivatives.In cyclohexane, the major CIDNP involves disproportionation of PhC(OH)CF3 radicals, although some 19F emission (E) is also o
Nasipuri,Bhattacharya
, p. 701 (1975)
Homoleptic cobalt(II) phenoxyimine complexes for hydrosilylation of aldehydes and ketones without base activation of cobalt(II)
Hori, Momoko,Ishikawa, Ryuta,Koga, Yuji,Matsubara, Kouki,Mitsuyama, Tomoaki,Shin, Sayaka
supporting information, p. 1379 - 1387 (2021/05/29)
Air-stable, easy to prepare, homoleptic cobalt(II) complexes bearing pendant-modified phenoxyimine ligands were synthesized and determined. The complexes exhibited high catalytic performance for reducing aldehydes and ketones via catalytic hydrosilylation, where a hydrosilane and a catalytic amount of the cobalt(II) complex were added under base-free conditions. The reaction proceeded even in the presence of excess water, and excellent functional-group tolerance was observed. Subsequent hydrolysis gave the alcohol in high yields. Moreover, H2O had a critical role in activation of the Co(II) catalyst with hydrosilane. Several additional results also indicated that the cobalt(II) center acts as an active catalyst in the hydrosilylation of aldehydes and ketones.
Formation of a hydride containing amido-zincate using pinacolborane
Ingleson, Michael J.,Nichol, Gary S.,Uzelac, Marina,Yuan, Kang
supporting information, p. 14018 - 14026 (2021/10/19)
Amido-zincates containing hydrides are underexplored yet potentially useful complexes. Attempts to access this type of zincate through combining amido-organo zincates and pinacolborane (HBPin)viaZn-C/H-BPin exchange led instead to preferential formation of amide-BPin and/or [amide-BPin(Y)]?(Y = Ph, amide, H), when the amide is hexamethyldisilazide or 2,2,6,6-tetramethylpiperidide and the hydrocarbyl group was phenyl or ethyl. In contrast, the use of a dipyridylamide (dpa) based arylzinc complex led to Zn-C/H-BPin metathesis being the major outcome. Independent synthesis and full characterisation of two LnLi[(dpa)ZnPh2] (L = THF,n= 3; L = PMDETA,n= 1) complexes,1and3, respectively, enabled reactivity studies that demonstrated that these species display zincate type reactivity (by comparison to the lower reactivity of the neutral complex (Me-dpa)ZnPh2,4, Me-dpa = 2,2′-dipyridyl-N-methylamine). This included1performing the rapid deprotonation of 4-ethynyltoluene and also phenyl transfer to α,α,α-trifluoroacetophenone in contrast to neutral complex4. Complex1reacted with one equivalent of HBPin to give predominantly PhBPin (ca.90%) and a lithium amidophenylzincate containing a hydride unit, complex7-A, as the major zinc containing product. Complex7-Atransfers hydride to an electrophile preferentially over phenyl, indicating it reacts as a hydridozincate. Attempts to react1with >1 equivalent of HBPin or with catecholborane led to more complex outcomes, which included significant borane and dpaZn substituent scrambling, two examples of which were crystallographically characterised. While this work provides proof of principle for Zn-C/H-BPin exchange as a route to form an amido-zincate containing a hydride, amido-organozincates that undergo more selective Zn-C/H-BPin exchange still are required.
