[Analysis of Carbon Emission Reduction Potential in the Pilot of a "Zero-free City" in Chongqing].

The construction of "zero-free cities" is an effective plan to achieve the carbon peak plan, reduce pollution and carbon emissions, and promote a circular economy. Based on the WARM model and Emission factor method, the total carbon emission reduction of solid waste sources and disposal in each field during the implementation of the zero-free city policy in Chongqing （2017-2021） was calculated, and the total carbon emission reduction of solid waste in each field in 2025 was predicted by scenario. The results showed that： ① After the implementation of cleaner production and green manufacturing policies in Chongqing, the generation intensity of general industrial solid waste decreased to 0.

Concise synthesis of 2-methoxyestradiol from 17β-estradiol through the C(sp)-H hydroxylation.

A four-step route for the synthesis of 2-methoxyestradiol (5) starting from 17β-estradiol (1) has been achieved with a 51% overall yield. The key step was the ruthenium-catalyzed ortho-C(sp)-H bond hydroxylation of aryl carbamates. Using dimethyl carbamate as the directing group, [RuCl(p-cymene)] as the catalyst, PhI(OAc) as the oxidant and trifluoroacetate/trifluoroacetic anhydride (1:1) as the co-solvent, the hydroxyl group could be singly installed at the 2-position of 3-dimethylcarbamoyloxyestradiol (2) with 65% yield.