We report a versatile method for cross-coupling of -sulfoximines with (hetero)aryl chlorides, as well as bromide and sulfonate electrophiles, that makes use of the air-stable, commercial precatalyst (PhPAd-DalPhos)Ni(-tol)Cl. Under optimized conditions a diverse electrophile scope is established, including the -arylation of the pharmaceutical Clozapine. While 5 mol % Ni and 80 °C are commonly employed in this chemistry, successful examples utilizing 1 mol % Ni and/or 25 °C are presented.
View Article and Find Full Text PDFHuman-mediated changes in island vegetation are, among others, largely caused by the introduction and establishment of non-native species. However, data on past changes in non-native plant species abundance that predate historical documentation and censuses are scarce. Islands are among the few places where we can track human arrival in natural systems allowing us to reveal changes in vegetation dynamics with the arrival of non-native species.
View Article and Find Full Text PDFThe impacts of human-induced environmental change that characterize the Anthropocene are not felt equally across the globe. In the tropics, the potential for the sudden collapse of ecosystems in response to multiple interacting pressures has been of increasing concern in ecological and conservation research. The tropical ecosystems of Papua New Guinea are areas of diverse rainforest flora and fauna, inhabited by human populations that are equally diverse, both culturally and linguistically.
View Article and Find Full Text PDFPurpose Early motor abilities (gesture, oral motor, and gross/fine skills) are related to language abilities, and this is not due to an association with cognitive or symbolic abilities: Oral motor skills are uniquely associated with language abilities at 21 months of age. It is important to determine whether this motor-language relationship continues beyond the earliest stage of language development to understand language acquisition better and better predict which children may have lasting language difficulties. Method In this longitudinal study, we assessed language comprehension and production, oral motor skill, gross/fine motor skill, and meaningless manual gesture at ages 3 years ( = 89) and 4 years ( = 71), comparing the contribution of motor skill and earlier (at 21 months of age) language ability.
View Article and Find Full Text PDFIslands are among the last regions on Earth settled and transformed by human activities, and they provide replicated model systems for analysis of how people affect ecological functions. By analyzing 27 representative fossil pollen sequences encompassing the past 5000 years from islands globally, we quantified the rates of vegetation compositional change before and after human arrival. After human arrival, rates of turnover accelerate by a median factor of 11, with faster rates on islands colonized in the past 1500 years than for those colonized earlier.
View Article and Find Full Text PDFThe development of Ni-catalyzed C-N cross-couplings of sulfonamides with (hetero)aryl chlorides is reported. These transformations, which were previously achievable only with Pd catalysis, are enabled by use of air-stable (L)NiCl(o-tol) pre-catalysts (L=PhPAd-DalPhos and PAd2-DalPhos), without photocatalysis. The collective scope of (pseudo)halide electrophiles (X=Cl, Br, I, OTs, and OC(O)NEt ) demonstrated herein is unprecedented for any reported catalyst system for sulfonamide C-N cross-coupling (Pd, Cu, Ni, or other).
View Article and Find Full Text PDFAnthropogenic activities are contributing to the changing hydrology of rivers, often resulting in their degradation. Understanding the drivers and nature of these changes is critical for the design and implementation of effective mitigation strategies for these systems. However, this can be hindered by gaps in historical measured flow data.
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