protocol for the construction of 9-(diorganomethylidene)fluorenes through palladium-catalyzed coupling reactions of 2-iodobiphenyls with alkenyl bromides has been reported. The reaction proceeds through the C–H activation/oxidative addition/reduction elimination/intramolecular Heck coupling reaction to afford a series of 9-(diorganomethylidene)fluorenes with good yields. Control experiments demonstrate that
Synthesis of Benzo[<i>b</i>]fluoranthenes and Spiroacridines from Fluorene-Derived Alkenes and <i>N</i>-Arylimines via a Tandem Reaction with Benzynes
作者:Weihua Wang、Hongwei Wan、Guangfen Du、Bin Dai、Lin He
DOI:10.1021/acs.orglett.9b00659
日期:2019.5.17
Two tandem processes involving the cycloaddition of benzynes have been developed for the synthesis of polyaromatic hydrocarbons. Benzynes react with fluorene-derived alkenes through a tandem Diels–Alder reaction/dehydrogenation process to afford benzo[b]fluoranthenes in 35–87% yields. In addition, an unprecedented [2 + 2] cycloaddition/ring-opening sequence of benzynes and fluorene-derived N-arylimines
已经开发了涉及联苯的环加成的两个串联方法来合成聚芳族烃。通过串联Diels-Alder反应/脱氢过程,苯并zy与芴衍生的烯烃反应,以35-87%的收率得到苯并[ b ]芴。此外,前所未有的[2 + 2]苯并炔和芴衍生的N-芳基嘧啶的环加成/开环顺序可轻松获得螺cr啶,收率为38-79%。
An N-heterocyclic carbene-catalyzed switchable reaction of 9-(trimethylsilyl)fluorene and aldehydes: chemoselective synthesis of dibenzofulvenes and fluorenyl alcohols
作者:Yu-Chuan Ma、Jin-Yun Luo、Shi-Chu Zhang、Shu-Hui Lu、Guang-Fen Du、Lin He
DOI:10.1039/d1ob00065a
日期:——
carbene-catalyzed synthesis of dibenzofulvenes and fluorenyl alcohols was developed. In the presence of 10 mol% NHC (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and 4 Å molecular sieves, 9-(trimethylsilyl)fluorene undergoes an olefination reaction with aldehydes to produce dibenzofulvenes in 43–99% yields. However, on reducing the NHC loading to 1 mol% and with the addition of water, 9-(trimethylsilyl)fluorene
Herein, we described the selective synthesis of both alkylated and alkenylated fluorenes using a single SNS ligand derived nickel complex. The protocol was employed for a wide range of substrates, including substituted fluorenes and various alcohols including aliphaticalcohols with a distal double bond. To expand the synthetic utility, an antimalarial drug analogue, benflumetol, was synthesized, and
Amberlyst-A26-Mediated Corey–Chaykovsky Cyclopropanation of 9-Alkylidene-9<i>H</i>-fluorene under Continuous Process
作者:Moseen A. Shaikh、Akash S. Ubale、Boopathy Gnanaprakasam
DOI:10.1021/acs.joc.3c02260
日期:2024.2.16
of Amberlyst-A26 as a heterogeneous base. Several 9-alkylidene-9H-fluorene derivatives successfully undergo Corey–Chaykovsky cyclopropanation to afford spiro[cyclopropane-1,9′-fluorene] in excellent yields under the continuous-process module. Furthermore, continuous process for the cyclopropanation of 3-benzylideneindolin-2-one derivatives using Amberlyst-A26 as a heterogeneous base has been described