Calcium carbide as the acetylide source: transition-metal-free synthesis of substituted pyrazoles via [1, 5]-sigmatropic rearrangements. Issue 24 (10th November 2016)

• Record Type: Journal Article
• Authors: Yu, Yue; Huang, Wei; Chen, Yang; Gao, Bingjie; Wu, Wanqing; Jiang, Huanfeng
• Is Part Of: Green chemistry. Volume 18:Issue 24(2016)
• Page Start: 6445
• Page End: 6449
• Publication Date: 2016-11-10
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c6gc02776h
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Calcium carbide was used as the acetylide source to synthesize substituted pyrazoles via [3 + 2] cycloaddition/[1, 5] sigmatropic rearrangements. Abstract : Under transition-metal-free conditions, calcium carbide was used as the acetylide source to react with a wide range of N -tosylhydrazones derived from aldehydes or ketones, affording various substituted pyrazoles in good yields with high regioselectivities. The transformations go through [3 + 2] cycloadditions followed by [1, 5]-sigmatropic rearrangements, which are supported by deuterium-labeling experiments.