Efficient activation of aromatic C-H bonds for addition to C-C multiple bonds

Efficient electrophilic metalation of aromatic C-H bonds leading to new C-C bond formation through regio- and stereoselective addition to alkynes and alkenes has been realized by a catalytic amount (0.02 to 5 mole percent) of palladium(II) or platinum(II) compounds in a mixed solvent containing trifluoroacetic acid at room temperature. Various arenes undergo unexpected selective trans hydroarylation to terminal or internal C&cjs0812;C bonds inter- and intramolecularly with high efficiency (up to a turnover number of 4500 for palladium), especially for electron-rich arenes, giving thermodynamically unfavorable cis-alkenes, and the oxygen- and nitrogen-containing heterocycles. The simplicity, generality, and efficiency of this process should be very attractive to the possible industrial application for the functionalization of arenes.

Non-metric tooth crown traits of the Thai, Aka and Yao tribes of northern Thailand.

A survey was made of Thai tribe members, who cultivate rice paddies in the flatlands of northern Thailand, and of the Aka and Yao tribes, who farm with the slash-and-burn method in a mountainous region of northern Thailand. Plaster casts of the upper and lower jaws of tribe members were taken. Seventeen non-metric traits of their tooth crowns were classified and compared with other Mongoloid populations in various regions and periods. It was observed that the Thai tribe had the Sundadont characteristics, typical of South-East Asians, but the Aka and Yao tribe had more Sinodont than Sundadont characteristics, typical of North-East Asians. The regional and temporal variations of crown morphology in South-East Asia suggest earlier setting of the Thai tribe than the Aka and Yao tribes in this region. Moreover, comparison of the tooth morphological and linguistic classifications contradicts the traditional theory of the genealogy of the Thai language family. On the subject of the origin of modern South-East Asians, it is suggested that there has not been a gene flow of Sinodonty into Sundadonty of the principal ethnic groups in Neolithic South-East Asia.

The internal orbital facial breadth and middle facial breadth in Mongoloid crania from Peru and east Asia, with special reference to their significance as a racial criterion.

The internal orbital facial breadth (BIFMO), middle facial breadth (BIZM) and their dimensional relationship in 789 crania from 3 Peruvian and 7 East Asian series were examined to determine a Mongoloid criterion. The results confirmed that BIZM was invariably greater than BIFMO in the Peruvian and East Asian series, and clearly different from the quoted European and African populations (Ducros, 1965). Further discussion, which referred to world population data by Woo and Morant (1934), showed that the relationship between BIZM and BIFMO was useful as a simple racial criterion to distinguish the Mongoloid series, except in special cases such as the Oceanians.

Morphological and anthropological aspects of human triangular deciduous lower first molar teeth.

The crown and root morphology, and bilateral occurrence of human deciduous lower first molars that exhibited a triangular occlusal outline, taken from excavated samples of Japanese, Jomonese and Iraqi origin, were investigated. The crowns of triangular teeth had smaller mesiodistal and larger buccolingual diameters than normally shaped deciduous lower first molars. An elongated buccolingual diameter was derived from the buccal projection of the distobuccal cusp and lingual projection of the portion between the metaconid and distolingual cusp. In this analysis, all triangular deciduous lower first molars in which root morphology could be observed were accompanied by additional distolingual roots. Correlation between the right- and left-hand sides of this trait was high.

Deciduous dental morphology of the prehistoric Jomon people of Japan: comparison of nonmetric characters.

Morphological variations of the deciduous dentition are as useful as those of the permanent dentition for determining the biological affinities of human populations. This paper provides material on morphological variations of deciduous teeth of the prehistoric Japanese population from the Late and the Latest Jomon Period (ca. 2000-ca. 300 B.C.). The expression of nonmetric traits of the deciduous teeth in the Jomon sample shows a closer affinity with modern Japanese and Native American samples than with American White, Asiatic Indian, and African samples. However, the frequency of shoveling in deciduous upper incisors in the Jomon sample is lower than those in modern Japanese and Native American samples. The Jomon sample also expresses a much higher frequency of cusp 6 in deciduous lower second molars than seen in modern Japanese, Ainu, and Native American samples. The frequency in the Jomon sample is equal to that in the Australian Aboriginal sample, which shows cusp 6 most frequently among the samples compared. A somewhat low incidence of incisor shoveling in the Jomon sample was also reported in the permanent dentition (Turner [1976] Science 193:911-913, [1979] Am. J. Phys. Anthropol. 51:619-635, [1987] Am. J. Phys. Anthropol. 73:305-321, [1990] Am. J. Phys. Anthropol. 82:295-317; T. Hanihara [1992] Am. J. Phys. Anthropol. 88:163-182, 88:183-196). However, the frequency of cusp 6 in the Jomon sample shows no significant difference from those of Northeast Asian or Native American samples in the permanent dentition (Turner [1987] Am. J. Phys. Anthropol. 73:305-321; T. Hanihara [1992] Am. J. Phys. Anthropol. 88:163-182, 88:183-196). Evidently, some nonmetric traits express an inter-group difference only in the deciduous dentition.