Morphological study of nymphal stages in Tenodera fasciata (Olivier, 1792) (Mantodea: Mantidae).

To date, no accurate identification method has been established for distinguishing mantis species of the genus Tenodera at all instar nymphal stages. In this paper, all instar nymphal stages of Tenodera fasciata (Olivier, 1792) are described in detail. This is the first step toward establishing an identification method for distinguishing the species from other members of the genus, particularly, T. angustipennis Saussure, 1869, which is sympatric with T. fasciata in Japan. Morphological differences between instars in nymphal stages, and between male and female in nymphal stages, were found. However, there was no difference between male and female 1st instars. Sex in nymphal stages are identified by the presence or absence of a crack at the posterior margin of the abdominal sternite IX between immature gonoplacs, the shape of the posterior margin of the sternites VII and IX, the occurrence of gonapophyses on the sternite VIII, and so on. Instars in nymphal stages are identified by body length, the length of discoidal spines of the profemur, the shape and size of the wing pads, the shape of abdominal sternite VII to IX, and so on.

Small-angle scattering study of tetra-poly(acrylic acid) gels.

Tetra-poly(acrylic acid) (tetra-PAA) gels were fabricated by cross-end coupling of azide (-N3) and alkyne (-C≡CH) terminated tetra-arm poly(tert-butyl acrylate)s. The structures of the tetra-PAA gels and their sols (tetra-PAA sols, i.e., tetra-PAA macromer solutions obtained by deprotection of tert-butyl groups) were investigated by small-angle X-ray and small-angle neutron scattering experiments in methanol, salt-free aqueous media, and salt solutions. The scattering functions, I(q), of the tetra-PAA sols in methanol were described by the Ornstein-Zernike (OZ) function, I q = I ( 0 ) / ( 1 + ξ 2 q 2 ) , whereas those of the gels were represented by the sum of the OZ function and a power-law function, I q ∼ A q b . Here, ξ is the correlation length, q is the magnitude of the scattering vector, A is a constant, and b is the scattering exponent. The OZ and the power-law functions represent the concentration fluctuations and cross-link inhomogeneities characteristic of gels, respectively. In salt-free aqueous media, there appeared a characteristic polyelectrolyte peak in the scattering functions, and the polymer concentration, C, dependence of the peak was similar for both sols and gels. In the presence of salt, both the scattering upturn for gels and the polyelectrolyte peak for both gels and sols were suppressed. Upon increasing the salt concentration, C s, the scattering intensity increased in the low q regions and the scattering functions were well fitted by the OZ function for both gels and sols.

Dearomatizing conversion of pyrazines to 1,4-dihydropyrazine derivatives via transition-metal-free diboration, silaboration, and hydroboration.

Pyrazines and substituted pyrazines undergo addition of boron reagents having B-B, Si-B, and H-B bonds under transition-metal-free conditions, leading to high-yield synthesis of N-borylated 1,4-dihydropyrazines and 1,2,3,4-tetrahydropyrazine.

Regioselective synthesis of 1,2-dihydropyridines by rhodium-catalyzed hydroboration of pyridines.

Pyridine undergoes addition of pinacolborane at 50 °C in the presence of a rhodium catalyst, giving N-boryl-1,2-dihydropyridine in a high yield. The selective 1,2-hydroboration also takes place in the reactions of substituted pyridines. In the reaction of 3-substituted pyridines, 3-substituted N-boryl-1,2-dihydropyridines are formed regioselectively.

(E)- and (Z)-ß-borylallylsilanes by alkyne silaboration followed by regio- and stereoselective double-bond migration.

Double take: ß-Borylallylsilanes have been synthesized by the regioselective silaboration of terminal alkynes followed by palladium-catalyzed double-bond migration of the resulting ß-borylalkenylsilanes. The stereoselectivity of the double-bond migration can be controlled by additives, thus leading to the stereocomplementary synthesis of (E)- and (Z)-ß-borylallylsilanes.

Palladium-catalyzed regioselective silaboration of pyridines leading to the synthesis of silylated dihydropyridines.

The addition of silylboronic esters to pyridine takes place in toluene at 50 °C in the presence of a palladium catalyst to give N-boryl-4-silyl-1,4-dihydropyridines in high yield. The regioselective 1,4-silaboration also proceeds in the reaction of 2-picoline and 3-substituted pyridines, whereas 4-substituted pyridines undergo 1,2-silaboration to give N-boryl-2-silyl-1,2-dihydropyridines regioselectively.

Switch of regioselectivity in palladium-catalyzed silaboration of terminal alkynes by ligand-dependent control of reductive elimination.

The regioselectivity in the addition of silylboronic esters to terminal alkynes can be switched by the choice of phosphorus ligands on the palladium catalysts. The silaboration proceeds with normal regioselectivity in the presence of (eta(3)-C(3)H(5))Pd(PPh(3))Cl (1.0 mol %) to give 1-boryl-2-silyl-1-alkenes in high yields. In sharp contrast, selective formation of the inverse regioisomers, 2-boryl-1-silyl-1-alkenes, takes place when the reaction is carried out with a palladium catalyst bearing P(t-Bu)(2)(biphenyl-2-yl). A reaction mechanism for the change of regioselectivity that involves reversible insertion/beta-boryl elimination steps is proposed.

Palladium-catalysed cis- and trans-silaboration of terminal alkynes: complementary access to stereo-defined trisubstituted alkenes.

Palladium-catalysed cis- and trans-silaboration of terminal alkynes has been developed via the addition of (chlorodimethylsilyl)pinacolborane, followed by a one-pot conversion of the chloro group on the silicon atom to an isopropoxy group.