669057-40-3Relevant academic research and scientific papers
Regio- and Stereoselective Synthesis of α-Chiral 2-Substituted 4-Bromothiazoles from 2,4-Dibromothiazole by Bromine-Magnesium Exchange. Building Blocks for the Synthesis of Thiazolyl Peptides and Dolabellin
Spie?, Alexandra,Heckmann, Golo,Bach, Thorsten
, p. 131 - 133 (2004)
Fragment 6 of thiazolyl peptide GE 2270 D2 and fragment 11 of dolabellin were synthesized stereoselectively from 2,4-dibromothiazole (1) in three (6, 44% overall yield) and five synthetic steps (11, 63% overall yield). Key to the success of the strategy w
2,4-Disubstituted thiazoles by regioselective cross-coupling or bromine-magnesium exchange reactions of 2,4-dibromothiazole
Gross, Stefan,Heuser, Stefan,Ammer, Carolin,Heckmann, Golo,Bach, Thorsten
scheme or table, p. 199 - 206 (2011/03/18)
Cross-coupling reactions occur on 2,4-dibromothiazole preferentially at the more electron-deficient 2-position. This fact can be favorably used to prepare 2-substituted 4-bromothiazoles, which serve as precursors for 2,4-disubstituted thiazoles. Protocols
Synthesis and configurational assignment of the amino alcohol in the eastern fragment of the GE2270 antibiotics by regio- and stereoselective addition of 2-metalated 4-bromothiazoles to α-chiral electrophiles
Delgado, Oscar,Heckmann, Golo,Mueller, H. Martin,Bach, Thorsten
, p. 4599 - 4608 (2007/10/03)
A synthesis of the eastern fragment of the thiazole peptide GE2270 A (1) has been developed. The synthetic approach relies on the regioselective functionalization of 2,4-dibromothiazole (5) via metalation and nucleophilic addition (at C2) or palladium-mediated cross-coupling (at C2 or C4). The stereochemistry at the N-bearing stereocenter was established by coupling of 2-metalated 4-bromothiazoles (4) to enantiomerically pure mandelic acid derivatives. Both the erythro (2) and threo (3) configurated amino alcohols were prepared with high diastereoselectivities depending on the electrophile employed. More specifically, the threo-configurated (S,R)-4-bromothiazolyl β-amino alcohol 6 was synthesized from O-TBS protected (R)-mandelonitrile in 62% yield. Its N-PMB protected (R,S)-enantiomer 20 was obtained from O-TBS protected (S)-mandelic aldehyde in 67% yield. The eryrthro-configurated (S,S)-4-bromothiazolyl β-amino alcohol 29 was prepared from O-TBS protected (S)-ethyl mandelate in four steps and 33% overall yield. The bithiazole moiety in the desired products 2 and 3 was finally established by the regioselective Negishi coupling of 2,4-dibromothiazole (5) and the 4-zincated, N-Boc protected thiazole derivatives of the diastereomeric 4-bromothiazolyl β-amino alcohols 6 and 29.
