Regioselective Dearomatization of N‐Alkylquinolinium and Pyridinium Salts under Morita‐Baylis‐Hillman Conditions. Issue 16 (1st August 2022)

• Record Type: Journal Article
• Authors: Pareek, Abhishek; Kalek, Marcin
• Is Part Of: Advanced synthesis & catalysis. Volume 364:Issue 16(2022)
• Page Start: 2846
• Page End: 2851
• Publication Date: 2022-08-01
• Subjects: C−C coupling -- Dearomatization -- Heterocycles -- Morita-Baylis-Hillman reaction -- N-alkylquinolinium salts -- Synthetic methods; Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.202200429
• Languages: English
• ISSNs: 1615-4150

Abstract

Abstract: Morita‐Baylis‐Hillman reaction employing N ‐alkylquinolinium salts as electrophiles has been developed. The reaction is promoted by DBU, which acts both as a catalyst activating the electron‐poor olefin as well as a base. The dearomatization occurs regioselectively at the C‐2 position, delivering a broad range of α‐(1, 2‐dihydroquinolin‐2‐yl)vinyl esters, ketones, and sulfones. The scope of the transformation has also been extended to N ‐alkylpyridinium salts. For this class of substrates a presence of at least moderately electron‐withdrawing substituent in the ring is necessary to attain good reactivity. In particular, N ‐alkylpyridinium salts containing an ester group undergo the dearomatization regioselectively at the C‐4 position, while nitrile and nitro moieties cause the non‐selective formation of products of the C‐2 and C‐6 additions. Abstract :