26431-43-6

Upstream product

• 109-99-9 tetrahydrofuran 
• 75-36-5 acetyl chloride 
• 35855-69-7 (E)-O,O'-diacetyl-1,2-diphenylethen-1,2-diol 
• 108-24-7 acetic anhydride 
• 37980-77-1 1,2-Bis-(trimethylsilyloxy)-1,2-diphenylethylen 
• 134-81-6 benzil 
• 21240-34-6 4,5-diphenyl-1,3-dioxol-2-one 
• 119-53-9 2-hydroxy-2-phenylacetophenone 
• 127-09-3 sodium acetate 
• 447-31-4 Desyl chloride 

Relevant academic research and scientific papers

Asymmetric Synthesis of Benzoin by SmI2-Mediated Enantioselective Protonation

Samarium (Z)-1,2-diphenylethen-1,2-diolate, which is considered to be an intermediate of a SmI2-mediated reduction of benzil, was protonated enantioselectively by quinidine to afford (R)-benzoin in 91 percentee.It was found that quenching the unreacted en

Cross-benzoin and Stetter-type reactions mediated by KO: T Bu-DMF via an electron-transfer process

The condensation of aromatic α-diketones (benzils) with aromatic aldehydes (benzoin-type reaction) and chalcones (Stetter-type reaction) in DMF in the presence of catalytic (25 mol%) KOtBu is reported. Both types of umpolung processes proceed with good efficiency and complete chemoselectivity. On the basis of spectroscopic evidence (MS analysis) of plausible intermediates and literature reports, the occurrence of different ionic pathways have been evaluated to elucidate the mechanism of a model cross-benzoin-like reaction along with a radical route initiated by an electron-transfer process to benzil from the carbamoyl anion derived from DMF. This mechanistic investigation has culminated in a different proposal, supported by calculations and a trapping experiment, based on double electron-transfer to benzil with formation of the corresponding enediolate anion as the key reactive intermediate. A mechanistic comparison between the activation modes of benzils in KOtBu-DMF and KOtBu-DMSO systems is also described.

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

A convenient heterogeneous continuous-flow procedure for the polarity reversal of aromatic α-diketones is presented. Propaedeutic batch experiments have been initially performed to select the optimal supported base capable to initiate the two electron-tra

Preparation of 1,2-diacetoxycycloalkenes and related acyclic systems

Preparation of the previously unavailable 1,2-diacetoxycycloalkenes from the corresponding 1,2-bis-(trimethylsilyloxy)cycloalkenes using 4-pyrrolidinopyridine as catalyst is described. A similar conversion of two acyclic systems is also reported.

Modification of the photochemical reactivity of α,β-diacetoxystilbene by adsorption onto a Fe3+-doped sepiolite: Comparison with the direct and 2,4,6-triphenylpyrylium-sensitized photolyses

Photolysis of α,β-diacetoxystilbene (1) adsorbed onto a Fe3+-doped sepiolite (Fe-Sp) leads to benzoic acid (3), 9,10-diacetoxyphenanthrene (5), diphenic anhydride (6), and benzil (7). While compounds 3, 5 and 6 are also observed in the direct irradiation of 1 in hexane solution, diketone 7 is formed under electron transfer conditions using 2,4,6-triphenylpyrylium tetrafluoroborate as photosensitizer. These results strongly suggest that formation of benzil (7) in the photolysis of 1 on Fe-Sp involves the intermediacy of 1+·, generated by single electron transfer from excited 1 to the iron active sites of the clay. In contrast to the unsubstituted stilbene, reactivity of 1+· with ground state molecular oxygen has been established by cyclic voltammetry through the current intensity decrease of the oxidation peak of 1 in the presence of oxygen. Finally, the thermodynamic feasibility of a direct electron transfer pathway between excited 1* and oxygen leading to the formation of a dioxetane intermediate is discussed.

FACILE HIGH YIELD SYNTHESIS OF ENEDIOL DIESTERS

Cathodic reductions of diaryl-1,2-diketones are carried out in the presence of acylating reagents.The respective enediol diesters are obtained in high yields.The products are formed by reaction of electrogenerated intermediates with the acylating agents.

Studies on the Occurence of Hydrogen Transfer, 67. Enediol Diesters by Acylating Electroreductive Dimerization of Acyl Chlorides with Lithium Amalgam

Aromatic, aliphatic, and aromatic-aliphatic acyl chlorides (and anhydrides) are transformed by lithium amalgam (Li/Hg) to cis- and/or trans enediol diesters 1-10 (acylating reductive dimerization), mostly in ca. 70percent yields.The influence of the solvent on the reaction course is investigated.Starting from 2,2'-biphenyldicarbonyl dichloride, the phenanthrene 7 is formed; phthalide 8 is the reaction-product using phthaloyl dichloride as starting material.Diphenylphosphinyl chloride is reduced by Li/Hg to tetraphenyldiphosphane dioxide (15).A reaction mechanism for the acylating reductive dimerization is proposed on the basis of the halve-wave potentials determined for 12 acyl chlorides and four 1,2-diketones.The latter are intermediates in the acylating reductive dimerization of the acyl chlorides.Enediol diesters are obtained starting from 1,2-diketones and Li/Hg in the presence of acyl chlorides.Trimethylsilyl chloride is unsuitable as a trap for the enediols; it is preferentially reduced at the Li/Hg interface.Tetrahydrofuran as solvent is transformed to RC(O)O-4-Cl by a known ring-opening acylation reaction in the presence of Lewis acids (LiCl or ZnCl2) formed by the decomposition of Li/Hg and Zn/Hg.

2,2-Dibutyl-1,3,2-dioxastannolens

Acyloins or their enediol carbonates (vinylene carbonates) react with dibutyltin oxide or dibutyltin dimethoxide to give 2,2-dibutyl-1,2,3-dioxastannolens . 119Sn N.m.r. and 119mSn Moessbauer spectra, and molecular weight measurements suggest that, in the solid state or in concentrated solution, the dioxastannolen (A) is associated, but the monomer is present in dilute solution.On heating, (A) decomposes into benzil and products which appear to be derived from dibutylstannylene, and it reacts with oxygen to give benzil and products derived from dibu- tyltin oxide.Acetyl chloride reacts to give cis-stilbene diacetate, but less reactive acylating agents (e.g. acetic anhydride or benzoyl chloride) give an increasing amount of the trans-diester and cyclic anhydrides (e.g. phthalic anhydride), and diacid chlorides (e.g. phosgene) give cyclic esters.

THE REACTION OF PHENYLLITHIUM WITH CARBON MONOXIDE

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.