α-Quaternary Mannich Bases through Copper-Catalyzed Amination-Induced 1,2-Rearrangement of Allylic Alcohols
作者:Wei-Zhi Weng、Jian-Guo Sun、Ping Li、Bo Zhang
DOI:10.1002/chem.201702428
日期:2017.7.21
A novel copper‐catalyzed amination‐induced 1,2‐rearrangement reaction of allylic alcohols has been developed under simple and mild conditions. The commercially available N‐fluorobenzenesulfonimide (NFSI) is employed as an amination reagent. In this transformation, not only alkyl, but also aryl substituents can efficiently undergo 1,2‐carbon atom migration, thereby providing an efficient and powerful
A catalytic allylic cation-induced intermolecular allylation-semipinacol rearrangement
作者:Ming-Hui Xu、Kun-Long Dai、Yong-Qiang Tu、Xiao-Ming Zhang、Fu-Min Zhang、Shao-Hua Wang
DOI:10.1039/c8cc04285c
日期:——
A catalytic intermolecular semipinacol rearrangement induced by allylic carbocations has been realized. This tandem reaction is highly efficient under the catalysis of ZnBr2, generating a wide range of α-homoallyl substituted ketones which contain all-carbon quaternary centres in good to excellent yields (up to 98%) with moderate to high diastereoselectivities (up to >20 : 1). Synthetic application
sulfonylation/semipinacol rearrangements of allylic alcohols were developed using cheap and stable RSO2Na (R = CF3, Ph) as reagents. Various β-trifluoromethyl and sulfonated ketones were obtained in moderate to excellent yields. This strategy provides a facile, direct, and complementary approach to construct all-carbon quaternary stereocenters. In addition, the reaction has the advantages of being chemical oxidant-free
Aerobic epoxidation of tertiary allylic alcohols remains a significant challenge. Reported here is an efficient and highly chemoselective copper‐catalyzed epoxidation and semipinacol rearrangement reaction of tertiary allylic alcohols with molecular oxygen. The solvent 1,4‐dioxane activates dioxygen, thereby precluding the addition of a sacrificial reductant.
Azides are building blocks of increasing importance in synthetic chemistry, chemical biology, and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, we report a safety study of ABX, which shows its hazardous nature. We introduce two derivatives, tBu-ABX and ABZ (azidobenziodazolone), with a better