Stereoselective Synthesis of Polysubstituted Conjugated Dienes Enabled by Photo-driven Sequential Sigmatropic Rearrangement

Angew Chem Int Ed Engl. 2024 Apr 8:e202400805. doi: 10.1002/anie.202400805. Online ahead of print.ABSTRACTWe here report a highly stereoselective method for the synthesis of polysubstituted conjugated dienes from α-aryl α-diazo alkynyl ketones and pyrazole-substituted unsymmetric aminals under mild conditions, which was driven by photo and involved 1,6-dipolar ion intermediate and quadruple sigmatropic rearrangements, was successfully developed. In this transformation, the cleavage of four bonds and the recombination of five bonds were achieved in one operational step. This protocol also provided a modular tool for constructing dienes via "one-pot" strategy from the three components of amines, pyrazol and α-alkynyl-α-diazoketones. The mechanistic investigation combining control experiments and therotical calculations indicated that the plausible reaction path underwent the 1,6-sigmatropic rearrangement of 1,6-dipolar ion intermediate instead of the 1,5-sigmatropic rearrangement of 1,5-dipolar ion intermediate.PMID:38587996 | DOI:10.1002/anie.202400805

Source: Angewandte Chemie - April 8, 2024 Category: Chemistry Authors: Xin Ji Chaoren Shen Yuhao Ni Zhi-Yao Si Si Yuzhu Wang Xinrong Zhi Yuting Zhao Huiling Peng Lu Liu Source Type: research