Co-reporter:Irina Protasova, Bekir Bulat, Nicole Jung, and Stefan Bräse
Organic Letters 2017 Volume 19(Issue 1) pp:34-37
Publication Date(Web):December 13, 2016
DOI:10.1021/acs.orglett.6b03252
Diazirines are one of the most prominent functionalities in labeling experiments in vivo and in vitro because they allow photochemical generation of carbenes. The strategy presented herein describes the formation of diaziridines, being essential precursors in diazirine syntheses, using solid-supported procedures with immobilized sulfonyl oximes. The solid-supported building blocks have been shown to be valuable intermediates for CuAAC and amidation reactions, offering the possibility to build complex compounds with diverse functionalities.
Co-reporter:Simone Gräßle, Sylvia Vanderheiden, Patrick Hodapp, Bekir Bulat, Martin Nieger, Nicole Jung, and Stefan Bräse
Organic Letters 2016 Volume 18(Issue 15) pp:3598-3601
Publication Date(Web):July 11, 2016
DOI:10.1021/acs.orglett.6b01609
A solid supported procedure for the synthesis of benzoxazinones, dihydropyrazinones, quinoxalinones, and dihydrooxazinones using immobilized oxazolones in combination with difunctional nucleophiles as cleavage agent is presented. The scope of the novel method has been demonstrated through subsequent modification of the parent oxazolone scaffold on solid supports using conversions with electrophiles or CuAAC reactions to give functionalized pyrazin-2-ones. The described method allows the synthesis of the target heterocycles in good yields via three to five steps on solid phases with only one chromatographic purification step.
Co-reporter:N. Jung, S. Grässle, D. S. Lütjohann, and S. Bräse
Organic Letters 2014 Volume 16(Issue 4) pp:1036-1039
Publication Date(Web):January 31, 2014
DOI:10.1021/ol403313h
A solid supported, odorless reagent for the dithioacetalization of aldehydes and ketones has been developed. The new reagent provides the dimercaptoalkane equivalent in combination with stoichiometric amounts of immobilized acid and enables the formation of dithianes and dithiolanes from aldehydes without any additives in good to very good yields with high purities. The reaction is chemoselective for aldehydes, but ketones can be reacted to the corresponding dithioketals if an additional Lewis acid such as BF3 is added.
Co-reporter:Nicole Jung, Bettina Stanek, Simone Gräßle, Martin Nieger, and Stefan Bräse
Organic Letters 2014 Volume 16(Issue 4) pp:1112-1115
Publication Date(Web):February 11, 2014
DOI:10.1021/ol4037133
The conversion of dithianylium cations into α-azo ketene dithioacetals via addition of polymer-bound diazonium precursors is shown. This new procedure allows the synthesis of α-azo ketene dithioacetals in one step within 2–90 min at rt and yields highly pure compounds that do not have to be purified in most cases. The α-azo ketene dithioacetals obtained have been shown to be valuable intermediates for the synthesis of hydrazones, α-halogenated α-azo ketene dithioacetals, and azo-functionalized dienes.
Co-reporter:Nicole Jung ;Dominic Lütjohann
Chemie in unserer Zeit 2013 Volume 47( Issue 6) pp:334-335
Publication Date(Web):
DOI:10.1002/ciuz.201390062