Ilya A. Cherepanov

Benzylic functionalization of (η6-alkylarene)chromium tricarbonyl complexes

Abstract A general method for the regioselective benzylic metallation of (η 6 -alkylarene)chromium tricarbonyl complexes on the action of lithium amides in THF under very mild conditions has been developed. Transmetallation reactions of the lithium derivatives thus obtained produce the corresponding benzylic organotin, zinc and copper chromium tricarbonyl complexes. Methods for the preparative benzylic functionalization of (η 6 -alkylarene)chromium tricarbonyl complexes have been developed, including carboxylation, α-hydroxyalkylation, γ-carbonylation, acylation, arylation, vinylation, heteroarylation and alkylation procedures. 5-Acetoxy-3-benzyl-1,4-methano-2,3,4,5-tetrahydro- IH -3-benzazepine has been prepared using the benzylic lithium derivative of the (η 6 -alkylarene)chromium tricarbonyl complex at the key step. This compound is a representative of the major class of physiologically active compounds known as C -norbenzomorphans.

Arenetricarbonylchromium complexes in the synthesis of 6,7-benzomorphanes

Abstract The action of sodium amide on tricarbonyl-η 6 -[1′,2′,3′,4′-tetrahydro-spiro(1,3-dioxolane-2,1′-naphthalene)]chromium followed by reaction with sodium bromoacetate gives tricarbonyl-η 6 -[1-(1,2,3,4-tetrahydro-4-oxonaphthalene)acetic acid]chromium ( 4 ). Some procedures to transform 4 into 1-( N -benzyl-2-aminoethyl)-1,2-dihydronaphthalene ( 10 )—a synthon to 6,7-benzomorphanes—are described. Cyclization of 10 by action of mercury(II) acetate yields 3-benzyl-1,2,3,4,5,6-hexahydro-1-hydroxy-2,6-methano-3-benzazocine ( 11 ).

Sydnonimines as exogenous NO donors

Chemical oxidation of a series of sydnonimine derivatives followed by NO release was studied. Substances having alkylamine substituents in the position 3 were shown to be considerably more potent NO donors in comparison with those having alkyl or aralkyl substituents in the position 3. It was suggested that the effect is mainly due to lowering of the activation energy of NO release upon stabilization of the cation formed competitevely by the amino group.

3-Lithiomethyl-4-phenylsydnone: A new type of organometallic derivatives of sydnones

An α-lithium derivative of 3-alkyl-substituted sydnone was first synthesized by direct metallation of 3-methyl-4-phenylsydnone withn-butyllithium. The reactivity of the compound obtained was studied. Reactions of 3-lithiomethyl-4-phenylsydnone with various electrophiles can serve as a convenient method for preparation of functionalized sydnones.

Synthesis of sulfur-containing sydnones

A method for the synthesis of 4-alkylthio- and 4-arylthiosydnones from 4-lithiosydnones and elementary sulfur was proposed.