The total synthesis of the pyridine-thiazole-containing natural product WS75624 B (1) is described. This synthesis proceeds via the Stille coupling of appropriately functionalized pyridine and thiazole components, and this paper details our studies on the use of the halogen dance reaction to prepare the desired thiazole. Various halogen dance reactions on thizoles are described, including a novel one-pot multistep reaction in which 2-bromothiazole is treated with LDA in the presence of a silyl chloride at -78 degrees C and quenched with an electrophile to provide the highly functionalized thiazole derivatives 27.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jo0351217 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Long-Range Halogen Dance Reaction in 4,5-Dihalogeno-2-(Sulfur-Containing Heterocyclyl)thiazole.
Chem Pharm Bull (Tokyo)
December 2024
Faculty of Pharmacy, Osaka Ohtani University.
We have investigated the base-induced long-range halogen dance reactions of 4,5-dibromo- or 4-bromo-5-iodothiazoles bearing sulfur-containing aromatic heterocycles at the C2-position. We have found that the reaction occurs in bithiazole regioisomers or (thiophenyl)thiazole derivatives, in which the C-5 halo group on the thiazole halogen donor regioselectively migrates to a halogen acceptor ring after treatment with lithium bis(trimethylsilyl)amide. The substrate with a thiophen-2-yl substituent required highly basic P
The Versatile and Strategic -Carbamate Directed Metalation Group in the Synthesis of Aromatic Molecules: An Update.
Chem Rev
June 2024
Department of Chemistry, Queen's University, Chernoff Hall, 9 Bader Lane, Kingston, Ontario K7K 2N1, Canada.
The aryl -carbamate (ArOAm) group is among the strongest of the directed metalation groups (DMGs) in directed metalation (DM) chemistry, especially in the form Ar-OCONEt. Since the last comprehensive review of metalation chemistry involving ArOAms (published more than 30 years ago), the field has expanded significantly. For example, it now encompasses new substrates, solvent systems, and metalating agents, while conditions have been developed enabling metalation of ArOAm to be conducted in a green and sustainable manner.
View Article and Find Full Text PDFUnsymmetrization of 1,8-Dibromonaphthalenes by Acid-Induced Halogen Dance Reaction.
J Org Chem
June 2024
School of Environmental Science and Engineering, Kochi University of Technology, Kami, Kochi 782-8502, Japan.
A simple and powerful tool for preparing uncommon bromoarenes via the unsymmetrization of a naphthalene ring was developed. The steric repulsion between the -bromo groups of 1,8-dibromonaphthalene distorts the naphthalene ring, allowing for nonelectronical activation. Ring distortion facilitates the 1,2-rearrangement of the bromo group, affording 1,7-dibromonaphthalene upon treatment with trifluoromethanesulfonic acid (halogen dance reaction).
View Article and Find Full Text PDFUltrafast Halogen Dance Reactions of Bromoarenes Enabled by Catalytic Potassium Hexamethyldisilazide.
Chemistry
April 2024
Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
Lochmann-Schlosser base, a stoichiometric combination of nBuLi and KOtBu, is commonly used as a superbase for deprotonating a wide range of organic compounds. In the present study, we report that catalytic potassium hexamethyldisilazide (KHMDS) exhibits higher catalytic activity than KOtBu for successive bromine-metal exchanges. Accordingly, 1-10 mol% of KHMDS dramatically enhances halogen dance reactions to introduce various electrophiles to bromopyridine, bromoimidazole, bromothiophene, bromofuran, and bromobenzene derivatives with the bromo group translocated from the original position.
View Article and Find Full Text PDFRegiocontrolled halogen dance of 2,5-dibromopyrroles using equilibrium between dibromopyrrolyllithiums.
Chem Commun (Camb)
January 2023
Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
A regiocontrolled halogen dance reaction of 2,5-dibromopyrroles is described. An ,-dimethylsulfamoyl group on the pyrrole nitrogen was especially effective for facilitating interconversion of the resulting 2,3- and 2,4-dibromopyrrolyllithiums, rendering the smooth halogen dance reaction. This method was applicable to the formal synthesis of atorvastatin.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!