Un grand nombre d'hydrocarbures insatures ont ete reduits par les metaux alcalins dans NH 3 liquide et les intermediaires carbanioniques ont ete detectes in situ par RMN et RPE. Les substrats sont partages en 3 groupes differents: a) ceux qui persistent comme dianions; b) ceux qui sont protones par NH 3 pour donner des anions monohydro; c) ceux qui subissent d'autres etapes de protonation/transfert
Un Grand nombre d'hydrocarbures insatures ont ete reduits par les metaux alcalins dans NH 3liquide et les intermediaires carbanioniques ont ete 在原位检测到 RMN 和 RPE。Les substrats sont partages en 3 groupes differents: a) ceux qui persistent comme dianions; b) ceux qui sont protones par NH 3 pour donner des anions monohydro;c) ceux qui subissent d'autres etapes de protonation/transfert d'electrons pour
Birch Reductions at Room Temperature with Alkali Metals in Silica Gel (Na<sub>2</sub>K-SG(I))
作者:Partha Nandi、James L. Dye、James E. Jackson
DOI:10.1021/jo900904f
日期:2009.8.21
Alkali metals in silica gel (the Na2K-SG(I) reagent) cleanly effect Birch reductions of substrates with at least two or more aromatic rings. The reaction conditions are alcohol-free, ammonia-free, and achieve excellent yields and high selectivities at room temperature.
Birch Reduction of Aromatic Compounds by Inorganic Electride [Ca<sub>2</sub>N]<sup>+•</sup>e<sup>–</sup> in an Alcoholic Solvent: An Analogue of Solvated Electrons
作者:Byung Il Yoo、Ye Ji Kim、YoungMin You、Jung Woon Yang、Sung Wng Kim
DOI:10.1021/acs.joc.8b02094
日期:2018.11.16
inorganic electride [Ca2N]+•e– promotes the Birch reduction of polycyclic aromatic hydrocarbons (PAHs) and naphthalene under alcoholic solvent in the vicinity of room temperature as a solid-type analogy to solvated electrons in alkali metal ammonia solutions. The anionic electrons from electride [Ca2N]+•e– are transferred to PAHs and naphthalene via alcoholysis in a polar cosolvent medium. It is noteworthy
在碱金属-氨溶液中通过溶剂化电子使芳香体系的桦木还原被广泛认为是使高度稳定的π共轭有机体系官能化的关键反应。尽管在还原剂和反应条件方面桦木还原方面有最新进展,但在温和条件下开发简单有效的桦木反应仍存在挑战。在这里,我们证明,无机醇[Ca 2 N] + • e –在室温附近的醇溶剂下,可促进多环芳烃(PAHs)和萘的桦木还原,这类似于固体中的溶剂化电子金属氨溶液。驻极体中的阴离子电子[Ca 2N] + • e –在极性助溶剂介质中通过醇解转移到PAHs和萘中。值得注意的是,向氢化产物的高转化率归因于98%的极高的电子转移效率。这种利用无机驻极体的简单方案为还原芳族化合物提供了直接而实用的策略,并为合成化学提供了出色的还原剂。
Hydrogen-protected acenes
作者:Andreas J. Athans、Jonathan B. Briggs、Wenling Jia、Glen P. Miller
DOI:10.1039/b700956a
日期:——
The first systematic study concerning the hydrogenation of acenes and acenequinones is presented. Phenyl substituted acenes and acenequinones are hydrogenated in excellent yield and with complete regioselectivity using HI–AcOH. The resulting H-protected acenes bear alternating aromatic and non-aromatic rings and are stable, soluble molecules that may be stored indefinitely and then deprotected to afford the parent acenes. In this manner, H-protected acenes have been utilized in the syntheses of several [60]fullerene-acene adducts. Buckminsterfullerene also hydrogenates in HI–AcOH yielding C3v symmetric C60H18.
这是首次对烯和烯醌的氢化进行系统研究。使用 HI-AcOH 对苯基取代的烯和烯醌进行氢化,产量极高且具有完全的区域选择性。生成的受 H 保护的烯具有交替的芳香环和非芳香环,是稳定的可溶性分子,可无限期储存,然后进行脱保护以得到母烯。通过这种方式,受 H 保护的烯已被用于合成多种 [60] 富勒烯-烯加合物。Buckminsterfullerene 也会在 HI-AcOH 中发生氢化反应,生成 C3v 对称的 C60H18。
Transition metal-free regioselective access to 9,10-dihydroanthracenes via the reaction of anthracenes with elemental phosphorus in the KOH/DMSO system
作者:Vladimir A. Kuimov、Nina K. Gusarova、Svetlana F. Malysheva、Boris A. Trofimov
DOI:10.1016/j.tetlet.2018.10.075
日期:2018.12
Anthracene and its 9- or 9,10-substituted (Me, Ph, Cl, Br) derivatives react with red phosphorus (Pn) in the KOH/DMSO superbase system at 85–120 °C to afford 9,10-dihydroanthracenes in good to excellent yields, thus providing simple and clean access to these extensively used dihydroaromatics.