Transition‐Metal‐Free Synthesis of Polyfunctional Triarylmethanes and 1,1‐Diarylalkanes by Sequential Cross‐Coupling of Benzal Diacetates with Organozinc Reagents
A variety of functionalized triarylmethane and 1,1‐diarylalkane derivatives were prepared via a transition‐metal‐free, one‐pot and two‐step procedure, involving the reaction of various benzal diacetates with organozincreagents. A sequential cross‐coupling is enabled by changing the solvent from THF to toluene, and a two‐step SN1‐type mechanism was proposed and evidenced by experimental studies. The
通过无过渡金属的一锅两步程序制备了各种官能化三芳基甲烷和1,1-二芳基烷烃衍生物,其中包括各种二乙酸苯亚缩酯与有机锌试剂的反应。通过将溶剂从 THF 更改为甲苯,可以实现顺序交叉偶联,并提出了两步 S N 1 型机理,并通过实验研究证明了这一点。该方法的合成效用通过几种生物学相关分子的合成得到进一步证明,例如抗结核剂、抗乳腺癌剂、鞘氨醇-1-磷酸(S1P)受体调节剂的前体和FLAP抑制剂。
Intramolecular Addition of Triarylmethanes to Alkynes Promoted by KO<i>t</i>Bu/DMF: A Synthetic Approach to Indene Derivatives
作者:Yan-yan Chen、Zhen-yu Chen、Niu-niu Zhang、Jia-hua Chen、Xue-jing Zhang、Ming Yan
DOI:10.1002/ejoc.201501356
日期:2016.1
been developed. The reaction was efficiently promoted by KOtBu/DMF without any transition-metal catalyst. A variety of indene derivatives were prepared in moderate to good yields. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. The reaction is proposed to proceed through the generation of a triphenylmethyl radical.
The C(sp(3))-H functionalization/carbocyclization reaction through the oxidative quenching of visible light photoredox catalysts is established for constructing functionalized 1H-indenes. The process is general for a wide range of benzylic C(sp(3))-H bonds and is highly compatible with common functional groups. Importantly, the visible light photoredox catalysts can be recovered and reused at least three times without loss of catalytic activity.
Modular Synthesis of 1<i>H</i>-Indenes, Dihydro-<i>s</i>-Indacene, and Diindenoindacene—a Carbon-Bridged <i>p</i>-Phenylenevinylene Congener
A variety of 1H-indenes, dihydro-s-indacenes, and diindenoindacenes, carbon-bridged phenylenevinylene derivatives, can be synthesized,in good to high yields using as a synthetic module a 3-lithioindene compound made available by reductive cyclization of an alkynylbenzene derivative. The planar analogues of oligophenylenevinylene compounds thus synthesized show physical properties beneficial for use as ambipolar organic semiconductor materials.