119-53-9Relevant articles and documents
THE REACTION OF PHENYLLITHIUM WITH CARBON MONOXIDE
Nudelman, N. Sbarbati,Vitale, Arturo A.
, p. 143 - 156 (1983)
Three main products are obtained from the reaction between phenyllithium and carbon monoxide, namely: benzophenone (I), benzoin (II) and α,α-diphenylacetophenone (III).Evidence is given for the existence of benzoyllithium as the first intermediate of the reaction and for the subsequent intermediates in the production of I, II and III.The basic sequences followed in the formation of those and of other minor products are outlined in the Scheme.Reaction conditions can be adjusted to obtain III in a high yield or to prevent further reaction of the first intermediate and obtain diarylalkylcarbinols, or substituted tetrahydrofurans.
Photocatalytic Coproduction of Deoxybenzoin and H2 through Tandem Redox Reactions
Luo, Nengchao,Hou, Tingting,Liu, Shiyang,Zeng, Bin,Lu, Jianmin,Zhang, Jian,Li, Hongji,Wang, Feng
, p. 762 - 769 (2020)
Photocatalytic H2 evolution from organic feedstocks with simultaneous utilization of photogenerated holes achieves solar energy storage and coproduces value-Added chemicals. Here we show visible-light H2 production from benzyl alcohol (BAL) with controllable generation of deoxybenzoin (DOB) or benzoin (BZ) through tandem redox reactions. Particularly, DOB synthesis circumvents the use of expensive feedstocks and environmentally unfriendly catalysts that are required previously. Under the irradiation of blue LEDs, the key of steering the major product to DOB rather than BZ is to decrease the conduction band bottom potentials of the ZnIn sulfide catalysts by increasing the Zn/In ratio, which results in the dehydration of intermediate hydrobenzoin (HB) to DOB proceeding in a redox-neutral mechanism and consuming an electron-hole pair. As a proof of concept, this method is used to synthesize DOB derivatives in gram scale.
α-Hydroxy ketones in high enantiomeric purity from asymmetric oxidation of enol phosphates with (salen) manganese(III) complex
Krawczyk, Ewa,Koprowski, Marek,Skowronska, Aleksandra,Luczak, Jerzy
, p. 2599 - 2602 (2004)
Optically active α-hydroxy ketones 4 have been prepared in high enantioselectivity by the catalytic, enantioselective oxidation of easily available and stable (E)-enol phosphates 2 by (salen) Mn(III) complex.
Iron borohydride pincer complexes for the efficient hydrogenation of ketones under mild, base-free conditions: Synthesis and mechanistic insight
Langer, Robert,Iron, Mark A.,Konstantinovski, Leonid,Diskin-Posner, Yael,Leitus, Gregory,Ben-David, Yehoshoa,Milstein, David
, p. 7196 - 7209 (2012)
The new, structurally characterized hydrido carbonyl tetrahydridoborate iron pincer complex [(iPr-PNP)Fe(H)(CO)(I·1-BH 4)] (1) catalyzes the base-free hydrogenation of ketones to their corresponding alcohols employing only 4.1atm hydrogen pressure. Turnover numbers up to 1980 at complete conversion of ketone were reached with this system. Treatment of 1 with aniline (as a BH3 scavenger) resulted in a mixture of trans-[(iPr-PNP)Fe(H)2(CO)] (4a) and cis-[(iPr-PNP)Fe(H) 2(CO)] (4b). The dihydrido complexes 4a and 4b do not react with acetophenone or benzaldehyde, indicating that these complexes are not intermediates in the catalytic reduction of ketones. NMR studies indicate that the tetrahydridoborate ligand in 1 dissociates prior to ketone reduction. DFT calculations show that the mechanism of the iron-catalyzed hydrogenation of ketones involves alcohol-assisted aromatization of the dearomatized complex [(iPr-PNP*)Fe(H)(CO)] (7) to initially give the Fe0 complex [(iPr-PNP)Fe(CO)] (21) and subsequently [(iPr-PNP)Fe(CO)(EtOH)] (38). Concerted coordination of acetophenone and dual hydrogen-atom transfer from the PNP arm and the coordinated ethanol to, respectively, the carbonyl carbon and oxygen atoms, leads to the dearomatized complex [(iPr-PNP*)Fe(CO)(EtO)(MeCH(OH) Ph)] (32). The catalyst is regenerated by release of 1-phenylethanol, followed by dihydrogen coordination and proton transfer to the coordinated ethoxide ligand.
Influence of magnesium(II) ions on cathodic reactions in aprotic solvents: the reduction of benzoate esters
Pletcher, Derek,Slevin, Louise
, p. 2005 - 2012 (1995)
The use of an Mg anode in an undivided cell alters the products from many electrosynthetic reactions.In an attempt to understand this phenomenon, the influence of MgII ions on the mechanism for the reduction of benzoate esters in DMF has been investigated.It is confirmed that the presence of MgII in solution leads to a change in the major reaction pathway from cleavage of the ester linkage (to give benzoate ion) to dimerisation (to a diketone).The dimer is then reduced further at the same potential.Cyclic voltammetry shows that in the absence of MgII, the ester radical anion is stable, while in the presence of MgII, the radical anion dimerises rapidly and the MgII also catalyses further reduction.Voltammmetry within the synthesis cell, however, shows that much of the MgII formed by dissolution of the anode is tied up by anionic products and that the dimerisation of the radical anion must occur well away from the cathode surface.
Pyridinium dichromate-assisted oxidative cleavage of α-functionalized benzylic alcohols by sodium percarbonate under phase-transfer conditions
Mohand,Levina,Muzart
, p. 2051 - 2059 (1995)
The course and the efficacy of the oxidation by sodium percarbonate of benzylic alcohols, α-substituted by a keto, hydroxy, ester or acid group, are dependent on the nature of both α-group and the solvent, and yields are usually improved by the presence of catalytic amounts of Cr(VI) species. The oxidative cleavage of the C(OH)-C(α) bond is the main process observed.
Azolium salts as effective catalysts for benzoin condensation and related reactions
Miyashita, Akira,Suzuki, Yumiko,Kobayashi, Motoi,Kuriyama, Naomi,Higashino, Takeo
, p. 509 - 512 (1996)
A catalytic ability of several azolium salts for benzoin condensation, the benzoylation of 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine, and oxidative aroylation was examined. We found that azolium salts having an imidazolium moiety, such as 1,4-dimethy
Postulation of Bis(thiazolin-2-ylidene)s as the Catalytic Species in the Benzoin Condensation Catalyzed by a Thiazolium Salt plus Base
Castells, J.,Lopez-Calahorra, F.,Domingo, L.
, p. 4433 - 4436 (1988)
Thiazolin-2-ylidenes generated by desilylation of 2-(trimethylsilyl)thiazolium ions are used as catalysts for the benzoin condensation.The experimental results together with theoretical calculations lead the postulate that bis(thiazolin-2-ylidene)s, and n
Mechanistic studies of the O2-dependent aliphatic carbon-carbon bond cleavage reaction of a nickel enolate complex
Berreau, Lisa M.,Borowski, Tomasz,Grubel, Katarzyna,Allpress, Caleb J.,Wikstrom, Jeffrey P.,Germain, Meaghan E.,Rybak-Akimova, Elena V.,Tierney, David L.
, p. 1047 - 1057 (2011)
The mononuclear nickel(II) enolate complex [(6-Ph2TPA)Ni(PhC(O)C(OH)C(O)Ph] ClO4 (I) was the first reactive model complex for the enzyme/substrate (ES) adduct in nickel(II)-containing acireductone dioxygenases (ARDs) to be reported. In this contribution, the mechanism of its O 2-dependent aliphatic carbon-carbon bond cleavage reactivity was further investigated. Stopped-flow kinetic studies revealed that the reaction of I with O2 is second-order overall and is ～ 80 times slower at 25 °C than the reaction involving the enolate salt [Me4N][PhC(O) C(OH)C(O)Ph]. Computational studies of the reaction of the anion [PhC(O)C(OH)C(O)Ph]- with O2 support a hydroperoxide mechanism wherein the first step is a redox process that results in the formation of 1,3-diphenylpropanetrione and HOO-. Independent experiments indicate that the reaction between 1,3-diphenylpropanetrione and HOO- results in oxidative aliphatic carbon-carbon bond cleavage and the formation of benzoic acid, benzoate, and CO:CO2 ( ～ 12:1). Experiments in the presence of a nickel(II) complex gave a similar product distribution, albeit benzil [PhC(O)C(O)Ph] is also formed, and the CO:CO2 ratio is ～ 1.5:1. The results for the nickel(II)-containing reaction match those found for the reaction of I with O2 and provide support for a trione/HOO- pathway for aliphatic carbon-carbon bond cleavage. Overall, I is a reasonable structural model for the ES adduct formed in the active site of Ni"ARD. However, the presence of phenyl appendages at both C(1) and C(3) in the [PhC(O)C(OH)C(O)Ph]- anion results in a reaction pathway for O2-dependent aliphatic carbon-carbon bond cleavage (via a trione intermediate) that differs from that accessible to C(1)- H acireductone species. This study, as the first detailed investigation of the O2 reactivity of a nickel(II) enolate complex of relevance to Ni"ARD, provides insight toward understanding the chemical factors involved in the O2 reactivity of metal acireductone species.
On the reactivity and stability of electrogenerated N-heterocyclic carbene in parent 1-butyl-3-methyl-1H-imidazolium tetrafluoroborate: Formation and use of N-heterocyclic carbene-CO2 adduct as latent catalyst
Feroci, Marta,Chiarotto, Isabella,Vecchio Ciprioti, Stefano,Inesi, Achille
, p. 95 - 101 (2013)
A simple electrolysis (under galvanostatic conditions) of the room temperature ionic liquid 1-butyl-3-methyl-1H-imidazolium tetrafluoroborate, BMIm-BF4, yields, after bubbling CO2 into the catholyte, theadduct NHC-CO2. The considerable stability of this NHC-CO 2 adduct, at room temperature, in the parentionic liquid as solvent, has been compared with the one of free NHC in the same BMIm-BF4. The BMIm-BF4solution containing NHC-CO2 adduct, suitably triggered (US irradiation or 120 °C), is able to releasefree NHC. The NHC-CO2 adduct usefulness has been demonstrated using it as efficient latent catalyst, inBMIm-BF4as solvent, in the benzoin condensation and in the oxidative esterification of cinnamaldehydewith benzyl alcohol.
