Water Scarcity Assessment of Hydropower Plants in China under Climate Change, Sectoral Competition, and Energy Expansion.

Hydropower plays a pivotal role in low-carbon electricity generation, yet many projects are situated in regions facing heightened water scarcity risks. This research devised a plant-level Hydropower Water Scarcity Index (HWSI), derived from the ratio of water demand for electricity generation to basin-scale available runoff water. We assessed the water scarcity of 1736 hydropower plants in China for the baseline year 2018 and projected into the future from 2025 to 2060. The results indicate a notable increase in hydropower generation facing moderate to severe water scarcity (HWSI >0.05), rising from 10% in 2018 to 24-34% of the national total (430-630 TWh), with a projected peak in the 2030s-2040s under the most pessimistic scenarios. Hotspots of risk are situated in the southwest and northern regions, primarily driven by decreased river basin runoff and intensified sectoral water use, rather than by hydropower demand expansion. Comparative analysis of four adaptation strategies revealed that sectoral water savings and enhancing power generation efficiency are the most effective, potentially mitigating a high of 16% of hydropower risks in China. This study provides insights for formulating region-specific adaptation strategies and assessing energy-water security in the face of evolving environmental and societal challenges.

Zinc-catalyzed regioselective C-P coupling of p-quinol ethers with secondary phosphine oxides to afford 2-phosphinylphenols.

The zinc triflate-catalyzed highly regioselective C-P cross coupling reaction of p-quinol ethers with secondary phosphine oxides is reported. The reaction provides a facile alternative method for the synthesis of 2-phosphinylphenols in good to high yields. Mechanistically, zinc triflate may serve as an oxophilic σ-Lewis acid to activate the C-O bond in p-quinol ether first. Then the regioselective attack of the phosphorus nucleophile at the α-carbon position takes place to form the C-P bond and give the product. In addition, α-alkynyl substituted p-quinol ethers also react with secondary phosphine oxides in the same reaction mode to give 6-alkynyl 2-phosphinylphenols in the presence of the zinc catalyst.