Synthesis of new enantiopure trans-3,4-diaminocaranes from (+)-3-carene
摘要:
A synthetic strategy to obtain new enantiopure trans-3,4-diaminocaranes derived from (+)-3-carene via a stereoselective methodology is described. The stereoselective preparation of 3,4-alpha-carene- or 3,4-beta-carene-epoxide is followed by a ring opening by sodium azide to obtain the azido-alcohols. Subsequent cyclization affords the corresponding aziridine diastereoisomers, which are converted to azido amines by opening of the aziridine rings by sodium azide and then reduced to the final diamine diastereoisomers. The absolute configurations of the final diamines and of novel intermediates are established by H-1 NMR spectra correlated with conformational analysis supported by molecular modeling. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of new enantiopure trans-3,4-diaminocaranes from (+)-3-carene
摘要:
A synthetic strategy to obtain new enantiopure trans-3,4-diaminocaranes derived from (+)-3-carene via a stereoselective methodology is described. The stereoselective preparation of 3,4-alpha-carene- or 3,4-beta-carene-epoxide is followed by a ring opening by sodium azide to obtain the azido-alcohols. Subsequent cyclization affords the corresponding aziridine diastereoisomers, which are converted to azido amines by opening of the aziridine rings by sodium azide and then reduced to the final diamine diastereoisomers. The absolute configurations of the final diamines and of novel intermediates are established by H-1 NMR spectra correlated with conformational analysis supported by molecular modeling. (C) 2011 Elsevier Ltd. All rights reserved.
Titanium and Cobalt Bimetallic Radical Redox Relay for the Isomerization of N-Bz Aziridines to Allylic Amides
作者:Song Lin、Devin P. Wood、Weiyang Guan
DOI:10.1055/s-0037-1610779
日期:2021.11
Herein a bimetallic radical redox-relay strategy is employed to generate alkyl radicals under mild conditions with titanium(III) catalysis and terminated via hydrogen atom transfer with cobalt(II) catalysis to enact base-free isomerizations of N-Bz aziridines to N-Bz allylic amides. This reaction provides an alternative strategy for the synthesis of allylic amides from alkenes via a three-step sequence
Direct and Stereospecific Synthesis of
<i>N</i>
‐H and
<i>N</i>
‐Alkyl Aziridines from Unactivated Olefins Using Hydroxylamine‐
<i>O</i>
‐Sulfonic Acids
作者:Zhiwei Ma、Zhe Zhou、László Kürti
DOI:10.1002/anie.201705530
日期:2017.8.7
A RhII-catalyzed direct and stereospecific N-H- and N-alkyl aziridination of olefins is reported that uses hydroxylamine-O-sulfonic acids as inexpensive, readily available, and nitro group-free aminating reagents. Unactivated olefins, featuring a wide range of functional groups, are converted into the corresponding N-H or N-alkyl aziridines in good to excellent yields. This operationally simple, scalable
Metal- and Additive-Free Intermolecular Aziridination of Olefins Using N-Boc-O-tosylhydroxylamine
作者:Jawahar L. Jat、Bhoopendra Tiwari、Dinesh Chandra、Puneet Kumar、Vikram Singh
DOI:10.1055/a-1879-7974
日期:2022.10
A metal and additive-free stereospecific direct N-H and N-Me aziridination of inactivated olefins is disclosed using N-Boc-O-tosylhydroxylamine (TsONHBoc) as an aminating agent in hexafluoroisopropanol (HFIP). The use of TsONHBoc, which generates the free aminating agent in situ under the reaction conditions, has several inherent advantages over other similar agents, such as low cost, easy access