Andrei A. Vasil'ev

A versatile and convenient protocol for the stereocontrolled synthesis of olefinic insect pheromones

A combination of the Horner-Emmons synthesis of alkyl 2,4-dienoates with their hydrogenation over complex L.Cr(CO)3 catalysts (L = 3CO or arene) provides a versatile, stereocontrolled and operationally simple approach to the (Z)-disubstituted, (Z)-trisubstituted, (E)-trisubstituted alkenes and skipped (Z,Z)-disubstituted diolefins with a homoallylic type of functionally. This protocol, sometimes supplemented by an enzymatic hydrolysis, was successfully applied to the synthesis of configurationally pure (gp > or = 98%) pheromones of the furniture carpet beetle, dry bean beetle, rusty grain beetle, square-necked grain beetle and a trail-following pheromone mimic for subterranean termites.

Thiophosphoryl-, Thiophosphoryloxy-, and Thiophosphorylamino-Benzene Derivatives as Novel Classes of Hybrid Pincer Ligands

Abstract The synthetic approaches to novel families of SCE (E = S′,N,O) hybrid pincer-type ligands bearing thophosphoryl, thiophosphoryloxy, and thiophosphorylamino groups in various combinations with thiophosphoryl-, thiocarbamoyl-, and imine- (including that of benzothiazole ring) donating functions have been developed. All of the ligands readily undergo direct cyclometallation (metal = Pd(II), Pt(II)) to afford 5,5- or 5,6-membered pincer complexes. Palladium complexes displayed from high to excellent catalytic performance in the Suzuki cross-coupling reaction of aryl bromides and phenylboronic acid and the higher asymmetry for a complex served as a factor of its higher catalytic activity.

Cross-coupling of polychloroarenes with phenylboronic acid and organozinc compounds catalyzed by palladium complexes

Hexachlorobenzene and 1,2,4,5-tetrachlorobenzene react with phenylboronic acid by a C—C cross-coupling mechanism with a Pd(dba)2/P(But)3 system (dba is dibenzylideneacetone) or palladium-azole complexes as catalysts, or with organozinc compounds in the presence of Pd(PPh3)4 to afford substitution products of one or two chlorine atoms in moderate yields.

Synthesis of 3(Z)-dodecen-12-olide - an aggregation pheromone of the flat grain beetle Cryptolestes pusillus (Coleoptera : Cucujidae)

Abstract3(Z)-Dodecen-12-olide, an aggregation pheromone of the flat grain beetle, was obtained using 1,4-cis-hydrogenation of ethyl 12-hydroxydodeca-2,4-dienoate as a key step. The dienoic ester was synthesized from 10-hydroxydec-2-enal, which, in turn, was prepared from its saturated precursorvia acetal α-bromination followed by phenylselenation/oxidative elimination/hydrolysis.

Access to 2,4-Dien-6-ynoic Acid Esters Using Selenium Chemistry. Formal Synthesis of Z,Z-Dodeca-3,6-dien-1-ol (Trail Pheromone Mimic of the Subterranian Termite Reticulitermes virginicus) and Z,Z-Dodeca-3,6-dien-11-olide (Aggregation Pheromone of the Grain Beetles Oryzaephilus mercartor and O. surinamensis)

Esters of 2,4-dien-6-ynoic acids were prepared from terminal acetylenes by lithiation, 1,2-addition to acrolein, orthoester Claisen–Johnson rearrangement and α-(4-methoxyphenyl)selenation/oxidative elimination to introduce the α,β-unsaturation.

Stereospecific syntheses of sex pheromones of the californian red scale and white peach scale (Homoptera:Diaspididae) based on 1,4-cis-hydrogenation of dienes

Stereospecific syntheses of (±)-3-methyl-6-isopropenyl-3(Z),9-decadien-1-yl acetate and (±)-3,9-dimethyl-6-isopropenyl-3(Z),9-decadien-1-yl propionate (the Racemoc forms of the pheromones of the scalesAonidiella aurantii andPseudaulascaspis pentagona) with a geometrical purity of the (Z)-trisubstituted double bond not lower than 99 % were performed. The key step in both syntheses was the 1,4-cis-hydrogenation of the corresponding ethyl 3-methyl-6-(1, 1-ethylenedioxyethyl)-2,4,9-decatrienoates catalyzed with chromium carbonyl complexes. These 2,4-dienes were obtained in five conventional steps including the alkylation of ethyl acetoacetate by the appropriate 1-bromo-3-butenes and the Horner-Emmons olefination of the corresponding α-branched aldehydes.

Reactions of polychlorophenyllithium compounds with electrophiles

Polychloroaromatic compounds lithiated by BunLi in THF react with several electrophilic agents of which aldehydes and epoxides seem to be the most promising from the preparative point of view.

Convenient synthesis of dodeca-1,3-diynyl ketones by the diacetylene zipper reaction

Dodeca-1,3-diynyl ketones were synthesized by isomerization of dodeca-5,7-diyne with H2N(CH2)2NHLi and treatment of the in situ prepared lithium derivative of dodeca-1,3-diyne with N-methoxy-N-methylcarboxamides.

A simple synthesis of 4E,7Z-tridecadien-1-yl acetate, a component of the sex pheromone of the potato mothPhtorimaea operculella (Lepidoptera:Gelehiidae)

A simple, five-step synthesis of the title compound was developed starting from commercially available 2,4-nonadienal. The overall yield of the pheromone is 29%, and the geometric purity of the Δ4 and Δ7 double bonds is ≥95%. TheZ configuration of the Δ7 bond results from the 1,4-cis-hydrogenation of the intermediate 1,4,6-undecatrien-3-ol in the presence of an (arene)chromium tricarbonyl complex, while theE configuration of the Δ4 bond arises in the Claisen-Johnson rearrangement occuring in the reaction of 1,5Z-undecadien-3-ol with trimethyl orthoacetate.