Reactions between Nitrile Oxides and Carbenium Ions: Synthesis of Benzoxazines, Oximes, and Amides through Intramolecular ortho or ipso Attack
摘要:
Reactions between nitrite oxides and benzylic carbocations are described. Different results were obtained when the carbocations were generated from the corresponding chlorides with different Lewis acids, with addition products such as benzoxazines, oximes, and amides being produced. Primary, secondary, and tertiary carbocations showed different reactivities. The product ratios strongly depended on the substituents on the aromatic ring of the benzylic carbocations. Evidence for the proposed mechanism is reported. ((C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
Lewis Acid‐Catalyzed Diastereoselective C−C Bond Insertion of Diazo Esters into Secondary Benzylic Halides for the Synthesis of α,β‐Diaryl‐β‐haloesters
作者:Fei Wang、Yoshihiro Nishimoto、Makoto Yasuda
DOI:10.1002/anie.202204462
日期:2022.7.18
Lewis acid-catalyzed carbon–carbon bond insertion of α-diazo esters into secondary benzylic halides is reported. Herein, the carbon chain elongation of acyclic benzylic halides and ring expansion in cyclic versions were realized to afford α,β-diaryl-β-halo carbonyl compounds with excellent diastereoselectivity. Computational study charted a specific mechanism involving the Lewis acid-promoted cleavage/re-formation