Generation of Indeno[1,2-<i>c</i>]pyrroles via a Pd-Catalyzed Reaction of 2-Alkynylbromobenzene with Propargylic Sulfonamide

A novel route for the efficient assembly of indeno[1,2-<i>c</i>]pyrrole derivatives via a palladium-catalyzed tandem reaction of 2-alkynylbromobenzene with propargylic sulfonamide is reported. The starting materials are easily available, and the reaction proceeds smoothly with good functional group tolerance

A New Insight into Palladium-Catalyzed Reaction of 2-Alkynylphenol with Carbon Monoxide

A novel and efficient pathway for the generation of 3-(benzofuran-3-ylmethylene)benzofuran-2(3<i>H</i>)-ones via a palladium-catalyzed carbonylative reaction of 2-alkynylphenol with carbon monoxide is described. The reaction proceeds through a double insertion of triple bonds during the reaction process. The products are obtained in good yields with high selectivity. A one-pot synthesis starting from 2-iodophenol and alkyne is presented as well

Generation of Indeno[1,2-<i>c</i>]pyrroles via a Pd-Catalyzed Reaction of 2-Alkynylbromobenzene with Propargylic Sulfonamide

A novel route for the efficient assembly of indeno[1,2-<i>c</i>]pyrrole derivatives via a palladium-catalyzed tandem reaction of 2-alkynylbromobenzene with propargylic sulfonamide is reported. The starting materials are easily available, and the reaction proceeds smoothly with good functional group tolerance

Route to Pyrazolo[5,1‑<i>a</i>]isoquinolines via a Copper-Catalyzed Tandem Reaction of 2‑Alkynylbromobenzene with Pyrazole

A copper-catalyzed tandem reaction of 2-alkynylbromobenzene and pyrazole is described that provides a facile route to pyrazolo­[5,1-<i>a</i>]­isoquinolines in good yields. During the reaction process, copper­(I)-catalyzed hydroamination and C–H activation are involved

Diastereodivergent Asymmetric Carboamination/Annulation of Cyclopropenes with Aminoalkenes by Chiral Lanthanum Catalysts

Stereodivergent asymmetric catalysis is an important technology that can allow efficient access to various stereoisomers of a given product with multiple stereocenters from the same set of starting materials, but its application to the synthesis of a highly strained cyclopropane compound has remained unexplored to date. We report here the first diastereodivergent enantioselective synthesis of bicyclic aminocyclopropanes by lanthanum-catalyzed asymmetric carboamination/annulation of cyclopropenes with aminoalkenes. This protocol features 100% atom efficiency, good yield (up to 90%), and high chemo- (up to >20:1) and stereoselectivity (up to >20:1 dr and 99% ee), constituting a unique route for the efficient synthesis of two different diastereoisomers of a given chiral bicyclic aminocyclopropane compound

Changes in Extremely Hot Summers over the Global Land Area under Various Warming Targets

<div><p>Summer temperature extremes over the global land area were investigated by comparing 26 models of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) with observations from the Goddard Institute for Space Studies (GISS) and the Climate Research Unit (CRU). Monthly data of the observations and models were averaged for each season, and statistics were calculated for individual models before averaging them to obtain ensemble means. The summers with temperature anomalies (relative to 1951–1980) exceeding 3σ (σ is based on the local internal variability) are defined as “extremely hot”. The models well reproduced the statistical characteristics evolution, and partly captured the spatial distributions of historical summer temperature extremes. If the global mean temperature increases 2°C relative to the pre-industrial level, “extremely hot” summers are projected to occur over nearly 40% of the land area (multi-model ensemble mean projection). Summers that exceed 5σ warming are projected to occur over approximately 10% of the global land area, which were rarely observed during the reference period. Scenarios reaching warming levels of 3°C to 5°C were also analyzed. After exceeding the 5°C warming target, “extremely hot” summers are projected to occur throughout the entire global land area, and summers that exceed 5σ warming would become common over 70% of the land area. In addition, the areas affected by “extremely hot” summers are expected to rapidly expand by more than 25%/°C as the global mean temperature increases by up to 3°C before slowing to less than 16%/°C as the temperature continues to increase by more than 3°C. The area that experiences summers with warming of 5σ or more above the warming target of 2°C is likely to maintain rapid expansion of greater than 17%/°C. To reduce the impacts and damage from severely hot summers, the global mean temperature increase should remain low.</p></div

Probability of “extremely hot” (>3σ) and “exceeding 5σ hot” (>5σ) summers in response to different magnitudes of warming relative to the pre-industrial level.

<p>Probability of “extremely hot” (>3σ) and “exceeding 5σ hot” (>5σ) summers in response to different magnitudes of warming relative to the pre-industrial level.</p

Spatial distribution of the “extremely hot” summers frequency from 1986 to 2005.

<p>The left, middle and right maps represent the GISS, CRU and averages of the individual models results, respectively.</p

Frequency of summer local temperature anomalies.

<p>The temperature anomalies (relative to the 1951–1980 mean) are divided by the local standard deviation of 1901–2005 and binned into intervals of 0.05. The local standard deviation is calculated from the long-term non-linearly detrended time series (details in data and method section). For the multi-model ensemble mean, this process was conducted for each model, and the final frequencies were averaged. The first, second and third graphs show the GISS, CRU and multi-model ensemble mean results, respectively. To better compare the results from observations and multi-model ensemble mean, the frequencies during the periods of 1951–1980 (reference period), 1976–1985, 1986–1995 and 1996–2005 are shown in the fourth graph.</p

Percentages of the areas with “extremely hot” (left) and “exceeding 5σ hot” (right) summers.

<p>The maps show the responses to different magnitudes of warming relative to pre-industrial level. The σ is calculated from the long-term non-linearly detrended time series (details in data and method section). The colors indicate the number of simulations. The line in the middle of each box represents the ensemble mean of the individual model results, and the upper and bottom edges of the box show the range of the 1σ uncertainty. The two bars outside the box represent the maximum and minimum simulation values.</p