NMR-Verified Dearomatization of 5,7-Substituted Pyrazolo[1,5-a]pyrimidines.

Tetrahydropyrazolo[1,5-a]pyrimidine (THPP) is an attractive scaffold for designing biologically active compounds. The most obvious way to obtain such compounds is to reduce pyrazolopyrimidines with complex hydrides, because the pyrimidine ring is reduced in the preference over the pyrazole ring. The presence of substituents at positions five and seven of pyrazolo[1,5-a]pyrimidines complicates the set of reaction products but makes it more attractive for medicinal chemistry because four possible stereoisomers can be formed during reduction.

11-Benzo[4,5]imidazo[1,2-]indol-11-one as a New Precursor of Azomethine Ylides: 1,3-Dipolar Cycloaddition Reactions with Cyclopropenes and Maleimides.

The possibility of generating azomethine ylides from 11-benzo[4,5]imidazo[1,2-a]indol-11-one and amino acids is shown for the first time. Based on the cycloaddition reactions of these azomethine ylides with cyclopropenes and maleimides, cyclopropa[a]pyrrolizines, 3-azabicyclo[3.1.

Structural data of phenanthrene-9,10-dicarbonitriles.

In this data article, we present the single-crystal XRD data of phenanthrene-9,10-dicarbonitriles. Detailed structure analysis and photophysical properties were discussed in our previous study, "Intermolecular interactions-photophysical properties relationships in phenanthrene-9,10-dicarbonitrile assemblies" (Afanasenko et al., 2020).

Regio- and Stereoselective 1,3-Dipolar Cycloaddition of Cyclic Azomethine Imines to Platinum(IV)-Bound Nitriles Giving Δ(2)-1,2,4-Triazoline Species.

The complex trans-[PtCl4(EtCN)2] (14) reacts smoothly at 25 °C with the stable cyclic azomethine imines R(1)CH═N(a)NC(O)CH(NHC(O)C6H4R(3))C(b)H(C6H4R(2))((a-b)) [R(1)/R(2)/R(3) = p-Me/H/H (8); p-Me/p-Me/H (9); p-Me/p-MeO/H (10); p-Me/p-Cl/p-Cl (11); p-MeO/p-Me/H (12); p-MeO/p-Cl/m-Me (13)], and the reaction proceeds as stereoselective 1,3-dipolar cycloaddition to one of the EtCN ligands accomplishing the monocycloadducts trans-[PtCl4(EtCN){N(a)═C(Et)N(b)C(O)CH(NHC(O)C6H4R(3))CH(C6H4R(2))N(c)C(d)HR(1)}])((a-d;b-c)) [R(1)/R(2)/R(3) = p-Me/H/H (15); p-Me/p-Me/H (16); p-Me/p-MeO/H (17); p-Me/p-Cl/p-Cl (18); p-MeO/p-Me/H (19); p-MeO/p-Cl/m-Me (20)]. Inspection of the obtained and literature data indicate that the cycloaddition of the azomethine imines to the C≡N bonds of HCN and of Pt(IV)-bound EtCN has different regioselectivity leading to Δ(2)-1,2,3-triazolines and Δ(2)-1,2,4-triazolines, respectively. Platinum(II) species trans-[PtCl2(EtCN){N(a)═C(Et)N(b)C(O)CH(NHC(O)C6H4R(3))CH(C6H4R(2))N(c)C(d)HR(1)}]((a-d;b-c)) [R(1)/R(2)/R(3) = p-Me/H/H (21); p-Me/p-Me/H (22); p-Me/p-MeO/H (23); p-Me/p-Cl/p-Cl (24); p-MeO/p-Me/H (25); p-MeO/p-Cl/m-Me (26)] were obtained by a one-pot procedure from 14 and 8-13 followed by addition of the phosphorus ylide Ph3P═CHCO2Me.

Synthesis and investigation of biological properties of modified 6-oxa-estra-1,3,5(10),8(9)-tetraenes.

To investigate the relationship between structure and biological activity of analogues of steroid estrogens we have developed the synthesis of 7α-methyl-6-oxa-estra-1,3,5(10),8(9)-tetraenes with cis- and trans-junction of C and D rings. We found that such compounds have stronger osteoprotective, cholesterol-lowering and antioxidant properties in comparison with uterotrophic activity; that is the advantage in comparison with clinically used 17α-ethynylestradiol.

Sky-blue luminescent Au(I)-Ag(I) alkynyl-phosphine clusters.

Treatment of the (AuC2R)n acetylides with phosphine ligand 1,4-bis(diphenylphosphino)butane (PbuP) and Ag(+) ions results in self-assembly of the heterobimetallic clusters of three structural types depending on the nature of the alkynyl group. The hexadecanuclear complex [Au12Ag4(C2R)12(PbuP)6](4+) (1) is formed for R = Ph, and the octanuclear species [Au6Ag2(C2R)6(PbuP)3](2+) adopting two structural arrangements in the solid state were found for the aliphatic alkynes (R = Bu(t) (2), 2-propanolyl (3), 1-cyclohexanolyl (4), diphenylmethanolyl (5), 2-borneolyl (6)). The structures of the compounds 1-4 and 6 were determined by single crystal X-ray diffraction analysis.

Intensely luminescent homoleptic alkynyl decanuclear gold(I) clusters and their cationic octanuclear phosphine derivatives.

Treatment of Au(SC(4)H(8))Cl with a stoichiometric amount of hydroxyaliphatic alkyne in the presence of NEt(3) results in high-yield self-assembly of homoleptic clusters (AuC(2)R)(10) (R = 9-fluorenol (1), diphenylmethanol (2), 2,6-dimethyl-4-heptanol (3), 3-methyl-2-butanol (4), 4-methyl-2-pentanol (4), 1-cyclohexanol (6), 2-borneol (7)). The molecular compounds contain an unprecedented catenane metal core with two interlocked 5-membered rings. Reactions of the decanuclear clusters 1-7 with gold-diphosphine complex [Au(2)(1,4-PPh(2)-C(6)H(4)-PPh(2))(2)](2+) lead to octanuclear cationic derivatives [Au(8)(C(2)R)(6)(PPh(2)-C(6)H(4)-PPh(2))(2)](2+) (8-14), which consist of planar tetranuclear units {Au(4)(C(2)R)(4)} coupled with two fragments [AuPPh(2)-C(6)H(4)-PPh(2)(AuC(2)R)](+).

Assembly of the Au-diphosphine helical cage molecules via alkynyl-μ4-methylydine ligand transformation.

The assembly of the gold(I)-diphosphine cages occurs via unprecedented transformation of the alkynyls into the μ(4)-methylydine ligands under basic conditions. These compounds demonstrate the equilibrium between the P↔M helical isomers and serve as hosts to accommodate small molecules (CH(2)Cl(2) and CS(2)).

Stereoselective cycloaddition of dibenzoxazepinium ylides to acetylenes and fullerene C60. Conformational behavior of 3-aryldibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepine systems.

Cycloaddition of dibenzoxazepinium ylides to acetylene carboxylates leads to cis-3-aryl-3,13b-dihydrodibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepinecarboxylates, which smoothly dehydrogenate to the corresponding pyrrole derivatives. The o-bromophenyl-substituted pyrrole, in contrast to the pyrroline analogue, demonstrates atropoisomerism. Stereoselective cycloaddition of dibenzoxazepinium ylides to fullerene C(60) gives rise to fulleropyrrolidines with cis-configuration.

Supramolecular luminescent gold(I)-copper(I) complexes: self-assembly of the Au(x)Cu(y) clusters inside the [Au3(diphosphine)3]3+ triangles.

The reactions between diphosphino-alkynyl gold complexes (PhC2Au)PPh2(C6H4)(n)PPh2(AuC2Ph) (n = 1, 2, 3) with Cu(+) lead to formation of the heterometallic aggregates, the composition of which may be described by a general formula [{Au(x)Cu(y)(C2Ph)2x}Au3{PPh2(C6H4)(n)PPh2}3](3+(y-x)) (n = 1, 2, 3; x = (n + 1)(n + 2)/2; y = n(n + 1)). These compounds display very similar structural patterns and consist of the [Au(x)Cu(y)(C2Ph)2x](y-x) alkynyl clusters "wrapped" in the [Au3(diphosphine)3](3+) triangles. The complex for n = 1 was characterized crystallographically and spectrally, the larger ones (n = 2, 3) were investigated in detail by NMR spectroscopy.

Unusual reaction between (nitrile)Pt complexes and pyrazoles: substitution proceeds via metal-mediated nitrile-pyrazole coupling followed by elimination of the nitrile.

The reaction of platinum(IV) complex trans-[PtCl4(EtCN)2] with pyrazoles 3,5-RR'pzH (R/R' = H/H, Me/H, Me/Me) leads to the formation of the trans-[PtCl4{NH=C(Et)(3,5-RR'pz)}2] (1-3) species due to the metal-mediated nitrile-pyrazole coupling. Pyrazolylimino complexes 1-3 (i) completely convert to pyrazole complexes cis-[PtCl4(3,5-RR'pzH)2] by elimination of EtCN upon reflux in a CH2Cl2 solution or upon heating in the solid state; (ii) undergo exchange at the imino C atom with another pyrazole different from that contained in the pyrazolylimino ligand. The reaction of trans-[PtIICl2(EtCN)2] and 3,5-RR'pzH, conducted under conditions similar to those for trans-[PtIVCl4(EtCN)2], is much less selective, and the composition of the products strongly depends on the pyrazole employed: (a) with pzH, the reaction gives a mixture of three products, i.

The synthesis, structure and dynamic behaviour of disubstituted alkenylphosphine derivatives of [Rh6(CO)16].

A series of [Rh(6)(CO)(16)] substituted derivatives containing Ph(2)P(alkenyl) ligands has been synthesized starting from the [Rh(6)(CO)(16-x)(NCMe)(x)](x= 1, 2) clusters and Ph(2)P((CH(2))(n)CH=CH(2))(n= 2, 3) phosphines. It was shown that the terminal alkenyl substituents in these phosphines easily undergo isomerization in the coordination sphere of the hexarhodium complexes to give the allyl -CH(2)CH=C(H)R (R = Me and Et) fragments coordinated through the double bond of the rearranged organic moieties. The solid-state structure of two clusters, [Rh(6)(CO)(14)(mu2,kappa3-Ph(2)PCH(2)CH=C(H)CH(3))](4) and [Rh(6)(CO)(14)(mu2,kappa3-Ph(2)PCH(2)CH=C(H)CH(2)CH(3))](8), was established by X-ray crystallography.