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Metal-Free Temperature-Controlled Regiodivergent Borylative Cyclizations of Enynes: BCl₃ -Promoted Skeletal Rearrangement.

ABSTRACT: Metal-free borylative cyclization of biphenyl-embedded 1,3,5-trien-7-ynes in the presence of simple and inexpensive BCl₃ provided synthetically useful borylated building blocks. The outcome of the process depends on the reaction temperature, with borylated phenanthrenes obtained at 60 °C and phenanthrene-fused borylated cyclobutanes formed at 0 °C. Based on DFT calculations, a mechanism for these novel transformations has been proposed, which involves an uncommon skeletal rearrangement, including migration of a methyl group and alkyne fragmentation, unprecedented in BCl₃ -promoted cyclization reactions.

SUBMITTER: Milian A

PROVIDER: S-EPMC9401584 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature

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Metal-Free Temperature-Controlled Regiodivergent Borylative Cyclizations of Enynes: BCl3 -Promoted Skeletal Rearrangement.

Milián Ana A Fernández-Rodríguez Manuel A MA Merino Estíbaliz E Vaquero Juan J JJ García-García Patricia P

Angewandte Chemie (International ed. in English) 20220524 28

Metal-free borylative cyclization of biphenyl-embedded 1,3,5-trien-7-ynes in the presence of simple and inexpensive BCl3 provided synthetically useful borylated building blocks. The outcome of the process depends on the reaction temperature, with borylated phenanthrenes obtained at 60 °C and phenanthrene-fused borylated cyclobutanes formed at 0 °C. Based on DFT calculations, a mechanism for these novel transformations has been proposed, which involves an uncommon skeletal rearrangemen ...[more]

PMID: 35510716

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