Sustainable Palladium-Catalyzed Tsuji-Trost Reactions Enabled by Aqueous Micellar Catalysis.

Palladium-catalyzed allylic substitution, or "Tsuji-Trost" reactions, can be run under micellar catalysis conditions featuring not only chemistry in water but also numerous combinations of reaction partners that require low levels of palladium, typically on the order of 1000 ppm (0.1 mol %). These couplings are further characterized by especially mild conditions, leading to a number of cases not previously reported in an aqueous micellar medium. Inclusion of diverse nucleophiles, such as N-H heterocycles, alcohols, dicarbonyl compounds, and sulfonamides is described. Intramolecular cyclizations further illustrate the broad utility of this process. In addition to recycling studies, a multigram scale example is reported, indicative of the prospects for scale up.

Organic selenium resin in solid phase synthesis and its application in constructing medicinally relevant small organic molecules.

Heterocyclic compounds are of high importance in constructing active drug intermediates library. The emergence of solid-phase and combinatorial chemistry has led to renewed interest in using organoselenium resins to library drug-like production. In this mini review, we summarize the construction of heterocyclic compounds libraries such as isoxazoles, oxadiazoles, triazoles, pyrimidines, pyrrolines, indolines, benzopyrans, furans etc. using organoselenium resins. And it provided efficient and practical ways for the preparation of a variety of well-defined functional heterocyclic compounds with the advantages of good yields, high purity, straightforward operations, broad range and high diversity of the products, lack of odor, and good stability of the resins, all of these give expression to green chemistry.

1-[4-(Difluoro-meth-oxy)phen-yl]-N-(3,4-dimeth-oxy-phen-yl)-1H-1,2,4-triazole-3-carboxamide.

Two crystallographically independent mol-ecules, A and B, with similar conformations are present in the asymmetric unit of the title compound, C(18)H(16)F(2)N(4)O(4). In mol-ecule A, the plane of the 1,2,4-triazole ring is tilted relative of the 4-difluoro-meth-oxy-substituted and the 3,4-dimeth-oxy-substituted benzene rings by 6.5 (2) and 16.4 (1)°, respectively. The -CHF(2) group is twisted away from the plane of the benzene ring, with a dihedral angle between the O-C bond of the OCHF(2) group and the plane of the adjacent phenyl ring of 38.6 (3)°. The corresponding parameters for mol-ecule B are 7.7 (1), 9.5 (2) and 25.2 (2)°. In both mol-ecules, the conformations are stabilized by intra-molecular N-H⋯N and C-H⋯O hydrogen bonds. There are also C-H⋯π contacts between the methyl groups and the benzene rings, and π-π stacking inter-actions between the benzene rings of adjacent parallel A mol-ecules [centroid-centroid distance = 3.8942 (17) Å]. π-π inter-actions are also observed between the triazole ring and one of the benzene rings of parallel B mol-ecules [centroid-centroid distance = 3.7055 (16) Å].

1-[4-(Difluoromethoxy)phenyl]-N-(2,3-dimethylphenyl)-1H-1,2,4-triazole-3-carboxamide.

In the mol-ecule of the title compound, C(18)H(16)F(2)N(4)O(2), the 1,2,4-triazole ring forms dihedral angles of 3.6 (2) and 14.9 (6)° with the 4-difluoro-meth-oxy-substituted benzene ring and the 2,3-dimethyl-substituted benzene ring, respectively. The OCHF(2) group is twisted away from the plane of the benzene ring, as shown by the C-O-C-C torsion angle of 145.8 (2)°. The conformation is stabilized by an inter-molecular N-H⋯N hydrogen bond. In the crystal, short C-H⋯O inter-actions lead to chains of mol-ecules.