An approach to access 1-substituted isoquinolones has been developed through the addition-cyclization of imines with Grignard reagents in the presence of 2,2'-dipyridyl. A number of substituted aromatic magnesium reagents were amenable to this process, and the desired products were obtained with excellent yields and outstanding diastereoselectivities ( dr > 99:1). The utility of this convenient approach is demonstrated by the formal synthesis of ( S)-cryptostyline II. Moreover, N-methylmorpholine (NMM) was found to be an effective additive for the formation of 3-substituted isoindolin-1-ones using one-pot addition-cyclization-deprotection of imine with Grignard reagents.
A highly efficient gold-catalyzed approach between N,Oacetals and ynamides for the construction of 6-(tert-butyldimethylsilyl)oxytetrahydropyrrolo[1,2-c][1,3]oxazin-1-ones was developed. This reaction tolerated a wide range of substituted N,O-acetals and TsN-substituted ynamides, leading to novel heterocycles in moderate to good yields and with excellent diastereoselectivities (dr > 99:1).
An efficient approach to access functionalized (2,3-dihydroisoxazol-4-yl) ketones has been developed by reacting nitrones 4 with ynones 7 or terminal ynones 10 in a one-pot fashion.
A series of chiral 5‐hydroxy isoxazolidines has been successfully synthesized through camphor sulfonyl hydrazine‐catalyzed asymmetric aza‐Michael addition reaction between N,O‐protected hydroxyamines and enals. Moderate yields with moderate to good enantioselectivities (up to 96% enantiomeric excess [ee]) were achieved. It provides an alternative asymmetric approach to preparing isoxazolidine derivatives.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.