A Novel Green Preparation of a, a''''-Bis (substituted benzylidene)-cycloalkanones Promoted by FeCl_3 6H-2O in Ionic Liquid

a, a'-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in [bmim][BF4] by using iron(III) chloride hexahydrate as a catalyst. It is shown that [bmim][BF4] and iron(III) chloride hexahydrate can be quantitatively recovered and be reused effectively for many times. Compared with the known methods, this novel process has the advantage of being an envkonmentally benign process together with good yields and mild reaction conditions.     

Metal-Free,Visible-Light-Induced Selective C−C Bond Cleavage of Cycloalkanones with Molecular Oxygen

A metal-free, visible-light-induced oxidative C−C bond cleavage of cycloketones with molecular oxygen is described. Cooperative Brønsted-acid catalysis and photocatalysis enabled selective C−C bond cleavage of cycloketones to generate an array of γ-, δ- and ϵ-keto esters under very mild conditions. Mechanistic studies indicate that singlet molecular oxygen (¹O₂) is responsible for this transformation.     

Convenient Synthesis of Geminal Bishydroperoxides by the Reaction of Ketones with Hydrogen Peroxide

A convenient procedure was developed for the synthesis of geminal bishydroperoxides by the sulfuric acid–catalyzed reaction of ketones with hydrogen peroxide in THF. Gem‐bishydroperoxides were prepared by the reactions of five‐ to seven‐membered cycloalkanones without additional purification in 80–95% yields with a purity of more than 95%; their acyclic analogs were prepared in 43–72% yields.     

An expedient synthesis of β-aralkyl cycloalkanones via the sequential conjugate addition of allyl arylacetates and Pd-catalyzed decarboxylative protonation protocol

An expedient protocol for the synthesis of β-aralkyl cycloalkanones was developed via the conjugate addition of allyl arylacetate to cycloalkenones and the following Pd-catalyzed decarboxylative protonation strategy.     

Animal bone meal as an efficient catalyst for crossed-aldol condensation

α,α′-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in water by using animal bone meal (ABM) or ABM modified as a catalyst. It is shown that ABM modified can be quantitatively recovered and be reused effectively for many times. A comparison of catalytic activity of these catalysts is discussed.     

Nano titania-supported sulfonic acid catalyzed synthesis of α,α′-bis(substituted-benzylidene)cycloalkanones and of their xanthene derivatives under solvent-free conditions

An efficient, rapid and green synthesis of α,α′-bis(substituted-benzylidene)cycloalkanones and their xanthene derivatives is reported under solvent-free conditions using nano titania-supported sulfonic acid (n-TSA) as a reusable catalyst. This method offers many advantages, such as environmental friendliness reaction conditions, simplicity, short reaction times, easy work-up, reusability of catalyst, and high yields of products. Eight new compounds are reported too.     

Synthesis of unsaturated dibasic acid esters from five-, six-, and seven-membered cycloalkanones

A new route to diesters of symmetrical octene-, decene-, and dodecenedioic acids was proposed. The ratio of the cis/trans-isomers was 1: 4. The synthesis involved oxidative splitting of five-, six-, and seven-membered cycloalkanones with hydrogen peroxide into the corresponding ω-alkenoic acids followed by esterification and metathesis over Re₂O₇/B₂O₃-Al₂O₃-SnMe₄. Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1942–1944, November, 2006.     

NH4H2PO4/SiO2: a recyclable,efficient heterogeneous catalyst for crossed aldol condensation reaction

Abstract

Crossed aldol condensation of aromatic aldehydes with cyclic ketones in the presence of catalytic amount of NH₄H₂PO₄/SiO₂ (as a safe, green, and cheap heterogeneous catalyst) under solvent-free condition afforded α,?-bis(substituted-benzylidene) cycloalkanones in high yields. This method is general with respect to all types of aromatic aldehydes and is an eco-friendly procedure. And the catalyst is easily prepared, stable, reusable, and efficient under the reaction conditions.     

Synthesis of medium-sized cyclic γ-haloketones by radical mediated ring-opening reaction of Lewis acid catalyzed (2+2)-cycloaddition products

Novel entry to synthesize medium-sized cycloalkanones is described. Thus, employment of catalytic (2+2)-cycloaddition for cyclic silyl enol ether followed by radical mediated ring-opening reaction provided medium-sized γ-halocycloalkanones.