Abstract3-Trifluoromethylpyrazole and its derivatives are of major interest to both the agrochemical and pharmaceutical industry for their diverse biological activities. Reported routes for the synthesis of 3-trifluoromethylpyrazoles are hindered by poor regioselectivity and limited scope of application. Here we report a directed Lewis base catalyzed intermolecular triazene-alkyne cycloaddition. It is featured that the combination of 1,8-diazabicyclo[5.4.0]undec-7-ene and 2,2,2-trifluorodiazoethane produces reactive triazene intermediates, which readily participate in cycloaddition reactions with terminal/internal alkynes, thus assembling densely substituted 3-trifluoromethylpyrazole scaffolds with environmental friendliness and operational simplicity. Synthetic utility of the protocol is highlighted by late-stage functionalization and scaffolds diversification. The practical value is also emphasized in potential platelet aggregation inhibitor synthesis.

An efficient method was developed towards the synthesis of alkenylphosphonates from simple olefins and phosphonate diesters. This method was enabled by the use of cheap and commercially available silver salts and TEMPO. This method exhibits of good functional group tolerance, specific (E)‐selectivity for all olefins and vinyl selectivity for aliphatic olefins. A radical mechanism was proposed, and TEMPO was involved in the product formation step.

A homogeneous photocatalytic recyclable system for the selective radical–radical cross-coupling of N-substituted amines and indoles has been established.

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