Synthesis of α-Amino Ketones from Terminal Alkynes via Rhodium-Catalyzed Denitrogenative Hydration of N-Sulfonyl-1,2,3-triazoles
摘要:
N-Sulfonyl-1,2,3-triazoles react with water in the presence of a rhodium catalyst to produce alpha-amino ketones in high yield. An intermediary alpha-imino rhodium(II) carbenoid undergoes insertion into the O-H bond of water. This transformation formally achieves 1,2-aminohydroxylation of terminal alkynes in a regioselective fashion when combined with the copper(I)-catalyzed 1,3-dipolar cycloaddition with N-sulfonyl azides.
Synthesis of 3-Pyrrolin-2-ones by Rhodium-Catalyzed Transannulation of 1-Sulfonyl-1,2,3-triazole with Ketene Silyl Acetal
作者:Rui-Qiao Ran、Jun He、Shi-Dong Xiu、Kai-Bing Wang、Chuan-Ying Li
DOI:10.1021/ol501514b
日期:2014.7.18
α-Imino rhodium carbenoids generated from 1-sulfonyl 1,2,3-triazole were applied to the 3 + 2 cycloaddition with ketene silyl acetal, offering a novel and straightforward synthesis of biologically interesting compound 3-pyrrolin-2-one with broad substrate scope.
Synthesis of Multifunctionalized 2-Carbonylpyrrole by Rhodium-Catalyzed Transannulation of 1-Sulfonyl-1,2,3-triazole with β-Diketone
作者:Wanli Cheng、Yanhua Tang、Ze-Feng Xu、Chuan-Ying Li
DOI:10.1021/acs.orglett.6b03179
日期:2016.12.2
A facile rhodium-catalyzed transannulation of 1-sulfonyl-1,2,3-triazoles with β-diketones was realized, and a series of multisubstituted 2-carbonylpyrroles were synthesized efficiently (up to 94% yield). The protocol features several advantages, such as readily available materials, mild reaction conditions, a concise operating procedure, a broad reaction scope, and excellent regioselectivity when benzoylacetone
of copper, rhodium, and gold formulate a one‐pot multistep pathway, which directly gives 2,5‐dihydropyrroles starting from terminal alkynes, sulfonyl azides, and propargylic alcohols. Initially, copper‐catalyzed 1,3‐dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1‐sulfonyl‐1,2,3‐triazoles, which then react with propargylic alcohols under the catalysis of rhodium. The resulting
Metal-free synthesis of imidazole by BF<sub>3</sub>·Et<sub>2</sub>O promoted denitrogenative transannulation of <i>N</i>-sulfonyl-1,2,3-triazole
作者:Dongdong Yang、Lihong Shan、Ze-Feng Xu、Chuan-Ying Li
DOI:10.1039/c8ob00083b
日期:——
BF3·Et2Opromoted metal-free denitrogenative transannulation of N-sulfonyl-1,2,3-triazole was reported. Rather than transition metals, BF3·Et2O was employed for the first time to promote the formation of α-diazoimines from N-sulfonyl-1,2,3-triazoles in nitriles, leading to the synthesis of various imidazoles. The protocol tolerates a broad range of functional groups and could also be applied to the
in a stereoselective manner. The reaction proceeds through generation of an α‐imino rhodium carbene complex, nucleophilic addition of the sulfur atom of a thioester onto the carbenoid carbonatom, and subsequent intramolecular migration of the acyl groupfrom the sulfur atom to the imino nitrogen atom. The method is successfully applied to a ring‐expansion reaction of thiolactones, thus leading to