Synthesis of 9-Ethoxycarbonyl-10(10aH)-oxo-5,6,7,8,8a,9-hexahydro-9,10a-anthracenecarbolactone and Related Compounds by Manganese(III) Mediated Cyclization
摘要:
Novel tetracyclic lactone (5a), 9-ethoxycarbonyl-10(10aH)-oxo-5,6,- 7,8,8a,9-hexahydro-9, 10a-anthracenecarbolactone, was obtained in 34.8% yield by oxidative cyclization of diethyl trans-2-benzoylcyclohexylmalonate (4a) with manganese(III) acetate dihydrate in the presence of sodium acetate in acetic acid.
Palladium catalyzed carbonylative generation of potent, pyridine-based acylating electrophiles for the functionalization of arenes to ketones
作者:Yi Liu、Angela M. Kaiser、Bruce A. Arndtsen
DOI:10.1039/d0sc03129a
日期:——
ultimate elimination of a new class of potent Friedel–Crafts acylating agent: N-acyl pyridinium salts. The latter can be exploited to modulate reactivity and selectivity in carbonylative arene functionalization chemistry, and allow the efficient synthesis of ketones with a diverse array of (hetero)arenes.
(254 nm) smoothly yielded hexahydrofluorenones and related structures. This photo‐Nazarov reaction could also be applicable to the substrates carrying β‐alkyl groups on the enone, which gave corresponding polycyclic rings containing quaternary centers. These photo‐electrocyclized products may prove useful for synthesizing a variety of natural products and their derivatives. Further application of this
Diaryl-dialkyl-substituted pyrazoles: regioselective synthesis and binding affinity for the estrogen receptor
作者:Gisele A. Nishiguchi、Alice L. Rodriguez、John A. Katzenellenbogen
DOI:10.1016/s0960-894x(02)00057-4
日期:2002.3
earlier, was expanded to allow the synthesis of the first series of these tetrasubstituted pyrazoles directly from alpha,beta-unsaturated ketones. The binding affinity of some of these pyrazoles for the estrogenreceptor (ER) subtypes ERalpha and ERbeta is very high, and the overall affinity pattern suggests the importance of three phenol substituents for high affinity, ERalpha-selective binding.
Negishi cross-coupling reactions are described. This method readily provides various enones from enol triflates and diorganozinc reagents with catalytic amounts of nickel(II) chloride–4,4′-dimethoxyl-2,2′-bipyridyl under carbonmonoxide atmosphere. The rate of carbonmonoxide insertion is increased by the addition of lithium or magnesium halides and the use of polar solvents. Alkenyl iodides can also
Electrochemical Fluorination of Vinyl Boronates through Donor‐Stabilized Vinyl Carbocation Intermediates**
作者:Benjamin Wigman、Woojin Lee、Wenjing Wei、Kendall N. Houk、Hosea M. Nelson
DOI:10.1002/anie.202113972
日期:2022.3.14
Vinyl carbocations were generated via single-electron oxidation of alkenyl boronates using electrical potentials. This electrochemical process enabled the formation of these reactive species without the use of Lewis or Brønsted acids. The intermediate vinyl carbocations were trapped with nucleophilic fluoride sources to yield vinyl fluorides; the production of new C−C, C−Cl, and C−Br bonds was also
乙烯基碳阳离子是通过使用电位对烯基硼酸盐进行单电子氧化而产生的。这种电化学过程能够在不使用 Lewis 或 Brønsted 酸的情况下形成这些反应性物质。中间乙烯基碳阳离子被亲核氟化物源捕获以产生氟乙烯;还证明了新的 C-C、C-Cl 和 C-Br 键的产生。