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Distal Allylic/Benzylic C-H Functionalization of Silyl Ethers Using Donor/Acceptor Rhodium(II) Carbenes.

ABSTRACT: Regio- and stereoselective distal allylic/benzylic C-H functionalization of allyl and benzyl silyl ethers was achieved using rhodium(II) carbenes derived from N-sulfonyltriazoles and aryldiazoacetates as carbene precursors. The bulky rhodium carbenes led to highly site-selective functionalization of less activated allylic and benzylic C-H bonds even in the presence of electronically preferred C-H bonds located α to oxygen. The dirhodium catalyst Rh₂ (S-NTTL)₄ is the most effective chiral catalyst for triazole-derived carbene transformations, whereas Rh₂ (S-TPPTTL)₄ works best for carbenes derived from aryldiazoacetates. The reactions afford a variety of δ-functionalized allyl silyl ethers with high diastereo- and enantioselectivity. The utility of the present method was demonstrated by its application to the synthesis of a 3,4-disubstituted l-proline scaffold.

SUBMITTER: Vaitla J

PROVIDER: S-EPMC7233467 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

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Distal Allylic/Benzylic C-H Functionalization of Silyl Ethers Using Donor/Acceptor Rhodium(II) Carbenes.

Vaitla Janakiram J Boni Yannick T YT Davies Huw M L HML

Angewandte Chemie (International ed. in English) 20200312 19

Regio- and stereoselective distal allylic/benzylic C-H functionalization of allyl and benzyl silyl ethers was achieved using rhodium(II) carbenes derived from N-sulfonyltriazoles and aryldiazoacetates as carbene precursors. The bulky rhodium carbenes led to highly site-selective functionalization of less activated allylic and benzylic C-H bonds even in the presence of electronically preferred C-H bonds located α to oxygen. The dirhodium catalyst Rh2 (S-NTTL)4 is the most ef ...[more]

PMID: 31908146

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