Syntheses of 7‐, 8‐ and 9‐Bromobenzotropolone, Cross‐Couplings of Their Methyl Ethers, and Deprotection to 7‐, 8‐ or 9‐Substituted Benzotropolones
Abstract Unprotected6,7‐benzotropolone and bromine were known to undergo an electrophilic substitution delivering the 7‐bromo derivative; it was carried on as its methyl ether. O‐ Acetyl‐6,7‐benzotropolone added bromine at the C8=C9 bond whereupon an amine‐induced E1 cb elimination led to the 8‐brominated benzotropolone acetate; ester cleavage with aqueous acetic acid and etherification with diazomethane delivered the corresponding methyl ether. O‐Methylbenzotropolone was brominated with N‐bromosuccinimide giving the 9‐brominated methyl ether. The mentioned bromobenzotropolone methyl ethers underwent Pd‐catalyzed C−C and C−B couplings. They comprised Suzuki‐Miyaura couplings (with R−BF3 K, R=Me, Bu, vinyl, Ph), Negishi couplings (with BuZnCl), Sonogashira couplings (with HC≡C−R, R=SiMe3, CH2 OH, Ph, Bu), Mizoroki‐Heck reactions (with methyl acrylate, methyl vinyl ketone, styrene, 3‐buten‐2‐ol), a carbonylative coupling, and Suzuki‐Miyaura borylations (with B2 Pin2). Subsequent O‐demethylations with BCl3 succeeded in most cases; they furnished a library of 34 O‐unprotected Br‐free benzotropolones, 31 of which were unknown before..
| Medienart: |
E-Artikel |
|---|
| Erscheinungsjahr: |
2022 |
|---|---|
| Erschienen: |
2022 |
| Enthalten in: |
Zur Gesamtaufnahme - volume:2022 |
|---|---|
| Enthalten in: |
European Journal of Organic Chemistry - 2022(2022), 37 |
| Beteiligte Personen: |
Koblischek, Philip [VerfasserIn] |
|---|
| BKL: |
|---|
| Anmerkungen: |
© 2022 Wiley‐VCH GmbH |
|---|
| Umfang: |
11 |
|---|
| doi: |
10.1002/ejoc.202200686 |
|---|
| funding: |
|
|---|---|
| Förderinstitution / Projekttitel: |
|
| PPN (Katalog-ID): |
WLY005079071 |
|---|
| LEADER | 01000caa a22002652 4500 | ||
|---|---|---|---|
| 001 | WLY005079071 | ||
| 003 | DE-627 | ||
| 005 | 20230307143604.0 | ||
| 007 | cr uuu---uuuuu | ||
| 008 | 230215s2022 xx |||||o 00| ||und c | ||
| 024 | 7 | |a 10.1002/ejoc.202200686 |2 doi | |
| 028 | 5 | 2 | |a EJOC_EJOC202200686.xml |
| 035 | |a (DE-627)WLY005079071 | ||
| 035 | |a (WILEY)EJOC202200686 | ||
| 040 | |a DE-627 |b ger |c DE-627 |e rda | ||
| 082 | 0 | 4 | |a 540 |q ASE |
| 084 | |a 35.50 |2 bkl | ||
| 100 | 1 | |a Koblischek, Philip |e verfasserin |4 aut | |
| 245 | 1 | 0 | |a Syntheses of 7‐, 8‐ and 9‐Bromobenzotropolone, Cross‐Couplings of Their Methyl Ethers, and Deprotection to 7‐, 8‐ or 9‐Substituted Benzotropolones |
| 264 | 1 | |c 2022 | |
| 300 | |a 11 | ||
| 336 | |a Text |b txt |2 rdacontent | ||
| 337 | |a Computermedien |b c |2 rdamedia | ||
| 338 | |a Online-Ressource |b cr |2 rdacarrier | ||
| 500 | |a © 2022 Wiley‐VCH GmbH | ||
| 520 | |a Abstract Unprotected6,7‐benzotropolone and bromine were known to undergo an electrophilic substitution delivering the 7‐bromo derivative; it was carried on as its methyl ether. O‐ Acetyl‐6,7‐benzotropolone added bromine at the C8=C9 bond whereupon an amine‐induced E1 cb elimination led to the 8‐brominated benzotropolone acetate; ester cleavage with aqueous acetic acid and etherification with diazomethane delivered the corresponding methyl ether. O‐Methylbenzotropolone was brominated with N‐bromosuccinimide giving the 9‐brominated methyl ether. The mentioned bromobenzotropolone methyl ethers underwent Pd‐catalyzed C−C and C−B couplings. They comprised Suzuki‐Miyaura couplings (with R−BF3 K, R=Me, Bu, vinyl, Ph), Negishi couplings (with BuZnCl), Sonogashira couplings (with HC≡C−R, R=SiMe3, CH2 OH, Ph, Bu), Mizoroki‐Heck reactions (with methyl acrylate, methyl vinyl ketone, styrene, 3‐buten‐2‐ol), a carbonylative coupling, and Suzuki‐Miyaura borylations (with B2 Pin2). Subsequent O‐demethylations with BCl3 succeeded in most cases; they furnished a library of 34 O‐unprotected Br‐free benzotropolones, 31 of which were unknown before. | ||
| 700 | 1 | |a Brückner, Reinhard |4 aut | |
| 773 | 0 | 8 | |i Enthalten in |t European Journal of Organic Chemistry |g 2022(2022), 37 |w (DE-627)WLY005046408 |x 10990690 |7 nnns |
| 773 | 1 | 8 | |g volume:2022 |g year:2022 |g number:37 |g extent:11 |
| 912 | |a GBV_USEFLAG_A | ||
| 912 | |a GBV_WLY | ||
| 936 | b | k | |a 35.50 |q ASE |
| 951 | |a AR | ||
| 952 | |d 2022 |j 2022 |e 37 |g 11 | ||