Enantioselective syntheses from dimethyl tartrate of 1,3,5-triazine homo-N-nucleoside analogs, containing a 1,4-dioxane moiety replacing the sugar unit in natural nucleosides, were accomplished. The triazine heterocycle in the nucleoside analogs was further substituted with combinations of NH(2), OH and Cl in the 2,4-triazine positions.

The Sn(IV) atom in the title compound, [Sn(C(4)H(9))(2)Cl(2)(C(12)H(8)N(2))], is chelated by the N-heterocycle; the n-butyl groups are trans to each other whereas the Cl atoms are cis to each other. The crystal studied was a non-merohedral twin with the minor domain being in a 15.8 (1)% proportion.

A hitherto unprecedented electronic situation has been observed for a substituted, pyridyl-functionalized phosphinine. In contrast to previous studies, this compound shows considerable π-donor properties as the result of the rather strong +M effect of the CH3S-substituent, changing the electronic properties of this low-coordinate and aromatic phosphorus heterocycle substantially.

In the title zwitterionic compound, C(15)H(19)NO(2)S, the six-membered heterocycle adopts a sofa conformation. The negative charge is delocalized along the carbonyl and enolate system on the ring and the positive charge is localized on the S atom. Two inter-molecular C-H⋯O inter-actions help to establish the packing.

Comparing the reactivity of the related lithium zincates [(THF)LiZn(TMP)(t)Bu(2)] (1) and [(PMDETA)LiZn(t)Bu(3)] (2) towards pyrazine discloses two new bimetallic approaches for the selective 2,5-dideprotonation and room temperature C-H alkylation of this sensitive heterocycle.

Geometric parameters of the title compound, C(24)H(20)N(2)O(2)S, are in the usual ranges. The central heterocycle makes dihedral angles of 41.29 (4) and 72.94 (5)° with the phenyl ring and the methoxy-phenyl ring, respectively.

In the title compound, C(20)H(15)N(3)O(2)·C(18)H(15)OP, the pyrimidinone heterocycle and the fused phenyl ring are inclined at 1.92 (7)°. Only the hy-droxy group is involved in hydrogen bonding, whereas the amino group is shielded from potential acceptors.

Copper-catalyzed cyclization of an oxime ester toward divergent heterocycle synthesis is reported. Oxime ester serves as an enamine precursor to cyclize with malononitrile and aldehydes for access to 2-aminonicotinonitriles in a one-pot reaction, while cyclizing with N-sulfonylimines leads to synthesis of pyrazolines.

[reaction: see text] The Friedländer synthesis of quinolines is an extensively employed protocol, yielding the desired heterocycle in a two-step reduction-condensation sequence. We have developed a mild, efficient, high-yielding single-step variant of this methodology, which employs SnCl(2) and ZnCl(2) to effect the reaction.

The inosine monophosphate cyclohydrolase (IMPCH) component (residues 1-199) of the bifunctional enzyme aminoimidazole-4-carboxamide ribonucleotide transformylase (AICAR Tfase, residues 200-593)/IMPCH (ATIC) catalyzes the final step in the de novo purine biosynthesis pathway that produces IMP. As a potential target for antineoplastic intervention, we designed IMPCH inhibitors, 1,5-dihydroimidazo...