Halogen-Bond-Induced Consecutive C<sub>sp</sub><sup>3</sup>–H Aminations via Hydrogen Atom Transfer Relay Strategy
作者:Fan Wu、Jeewani P. Ariyarathna、Navdeep Kaur、Nur-E Alom、Maureen L. Kennell、Omar H. Bassiouni、Wei Li
DOI:10.1021/acs.orglett.0c00081
日期:2020.3.20
The utilization of a halogen bond in a number of chemical fields is well-known. Surprisingly, the incorporation of this useful noncovalent interaction in chemical reaction engineering is rare. We disclose here an uncommon use of halogen bonding to induce intermolecular C-sp(3)-H amination while enabling a hydrogen atom transfer relay strategy to access privileged pyrrolidine structures directly from alkanes. Mechanistic studies support the presence of multiple halogen bond interactions at distinct reaction stages.
Catalyst-free aminobromination of alkenes with N-methyl-p-toluenesulfonamide as nitrogen resource
作者:Guangqian Zhang、Guanghui An、Jun Zheng、Yi Pan、Guigen Li
DOI:10.1016/j.tetlet.2009.12.059
日期:2010.2
A catalyst-free electrophilic aminobromination system was described with N-methyl-p-toluenesulfon-amide (p-TsNHCH3) and N-bromosuccinimide (NBS) as nitrogen and bromine resources. The reaction can give vicinal haloamines in good yields, excellent regioselectivities, and stereoselectivities under convenient and mild condition. The existence of N-methyl group in the nitrogen resource was found to play an important role in the formation of vicinal haloamine product. (C) 2009 Elsevier Ltd. All rights reserved.
Atmosphere- and Temperature-Controlled Regioselective Aminobromination of Olefins
作者:Wesley Zongrong Yu、Yi An Cheng、Ming Wah Wong、Ying-Yeung Yeung
DOI:10.1002/adsc.201600821
日期:2017.1.19
A complete switch of regioselectivity in the aminobromination of olefins is realized from delicate changes in the reaction temperature from 25 °C to 40 °C and the atmosphere from air to argon, under catalyst‐free conditions. The resulting α‐bromoamides can be transformed easily to high‐value compounds (e.g., Clobenzorex). Mechanistic studies revealed that the reaction went through a radical pathway