21403-38-3Relevant academic research and scientific papers
Light-Enabled Radical 1,4-Aryl Migration Via a Phospho-Smiles Rearrangement
De Abreu, Maxime,Belmont, Philippe,Brachet, Etienne
, p. 3758 - 3767 (2021/02/01)
Rearrangement reactions in organic chemistry are attractive strategies to build efficiently complex scaffolds, in just one step, from simple starting materials. Among them, aryl migrations are certainly one of the most useful and straightforward rearrangement for building attractive carbon-carbon bonds. Of note, anionic aryl migration reactions have been largely described compared to their radical counterparts. Recently, visible-light catalysis has proven its efficiency to generate such radical rearrangements due to the concomitant loss of a particle (often CO2 or SO2), which is the driving-force of the reaction. Here, we disclose a Smiles-type rearrangement, triggered by a phosphorus-containing unit (arylphosphoramidate), therefore called "phospho-Smiles"rearrangement, allowing a Csp2-Csp2 bond formation thanks to a 1,4-aryl migration reaction. In addition, combining this approach with a radical hydroamination/amination reaction produces an amination/phospho-Smiles cascade particularly attractive, for instance, to investigate the synthesis of the phthalazine core, a scarcely described scaffold of interest for medicinal chemistry projects.
Gold-Catalyzed Ring Expansion of Enyne-Lactone: Generation and Transformation of 2-Oxoninonium
Luo, Kui,Cao, Tongxiang,Jiang, Huanfeng,Chen, Lianfen,Zhu, Shifa
, p. 5856 - 5859 (2017/11/10)
An efficient gold-catalyzed ring-expansion reaction of enyne-lactones to form 2-oxoninonium intermediates is reported. The 2-oxoninonium generated in this work could undergo further 6π electrocyclization and aromatization reaction to produce different aromatic compounds.
Regioselective Synthesis of Polyheterohalogenated Naphthalenes via the Benzannulation of Haloalkynes
Lehnherr, Dan,Alzola, Joaquin M.,Lobkovsky, Emil B.,Dichtel, William R.
, p. 18122 - 18127 (2015/12/24)
Independent control of halide substitution at six of the seven naphthalene positions of 2-arylnaphthalenes is achieved through the regioselective benzannulation of chloro-, bromo-, and iodoalkynes. The modularity of this approach is demonstrated through the preparation of 44 polyheterohalogenated naphthalene products, most of which are difficult to access through known naphthalene syntheses. The outstanding regioselectivity of the reaction is both predictable and proven unambiguously by single-crystal X-ray diffraction for many examples. This synthetic method enables the rapid preparation of complex aromatic systems poised for further derivatization using established cross-coupling methods. The power and versatility of this approach makes substituted naphthalenes highly attractive building blocks for new organic materials and diversity-oriented synthesis.
Vinylogous Nicholas reactions in the synthesis of bi- and tricyclic cycloheptynedicobalt complexes
Kolodziej, Izabela,Green, James R.
, p. 10852 - 10864 (2015/11/17)
The Lewis acid mediated intramolecular Nicholas reactions of allylic acetate enyne-Co2(CO)6 complexes afford cycloheptenyne-Co2(CO)6 complexes in three manifestations. Electron rich aryl substituted alkyne complexes give tricyclic 6,7,x-benzocycloheptenyne complexes, with x = 5, 6, or 7. Allylsilane substituted complexes afford exo methylene bicyclic x,7-cycloheptenyne complexes (x = 6,7). The allyl acetate function may also be replaced by a benzylic acetate, to afford dibenzocycloheptyne-Co2(CO)6 complexes. Following reductive complexation, the methodology may be applied to the synthesis of the icetexane diterpene carbon framework.
Formation of condensed 1 H-pyrrol-2-ylphosphonates and 1,2-dihydropyridin- 2-ylphosphonates via Kabachnik-fields reaction of acetylenic aldehydes and subsequent 5-exo-dig or 6-endo-dig cyclizations
Buk?naitienè, Rita,Urbanaitè, Aurelija,?ikotienè, Inga
, p. 6532 - 6553 (2014/08/05)
Kabachnik-Fields reactions of various carbocyclic or heterocyclic acetylenic aldehydes together with subsequent Lewis acid catalyzed cyclizations have been studied. It was found that 5-exo-dig versus 6-endo-dig cyclization mode strongly depends on the structure of starting materials. Thus, nonaromatic acetylenic α-anilinomethylphosphonates underwent gold(III)-catalyzed or iodine-mediated 5-exo-dig cyclization to 1H-pyrrol-2-ylphosphonates. In contrast, electron-withdrawing heteroaromatic substrates formed 1,2-dihydropyridin-2-ylphosphonate ring containing materials via an exclusive 6-endo-dig ring-closure process. The dual mode of cyclization is possible only for α-amino (2-alkynylphenyl)methylphosphonates containing a benzene ring.
Copper catalyzed synthesis of highly substituted pyrrole and isoindole derivatives
Nandi, Sukla,Ray, Jayanta K.
, p. 6203 - 6206 (2011/11/29)
We have developed an efficient synthesis of highly substituted pyrrole and isoindole derivatives using copper(I) catalyst. This methodology is helpful for the synthesis of some quinones bearing annealed N-heterocyclic natural products.
Gold(I)-catalyzed tandem cyclization-selective migration reaction of 1,3-dien-5-ynes: Regioselective synthesis of highly substituted benzenes
Garcia-Garcia, Patricia,Martinez, Alberto,Sanjuan, Ana M.,Fernandez-Rodriguez, Manuel A.,Sanz, Roberto
supporting information; experimental part, p. 4970 - 4973 (2011/11/29)
Highly substituted benzene derivatives have been easily prepared in a regioselective way from readily available 1,3-hexadien-5-ynes through a gold(I)-catalyzed tandem reaction. The process involves an initial cyclization followed by a selective Wagner-Meerwein shift in which the migration preference seems to be determined by the ability to stabilize a positive charge.
Copper-catalyzed addition of water affording highly substituted furan and unusual formation of naphthofuran ring from 3-(1-alkenyl)-2-alkene-1-al
Jana, Rathin,Paul, Sunanda,Biswas, Anup,Ray, Jayanta K.
supporting information; experimental part, p. 273 - 276 (2010/03/26)
We have developed a novel one-pot reaction to generate highly substituted furan through the addition of water followed by oxidation and unusual cyclization to naphthofuran ring under the same reaction condition.
Gold-catalyzed intramolecular [3 + 2]-cycloaddition of arenyne-yne functionalities
Lian, Jian-Jou,Chen, Po-Chiang,Lin, Yau-Ping,Ting, Hao-Chun,Liu, Rai-Shung
, p. 11372 - 11373 (2007/10/03)
We report a new efficient intramolecular [3 + 2]-cycloaddition of unactivated arenyne (or enyne)-yne functionalities, catalyzed mainly by the AuPPh3SbF6 complex (2 mol %) under ambient conditions. The value of this cyclization is ref
Ring size and substituent effects in oxyanion-promoted cyclizations of enyne-allenes: Observation of a Myers-Saito cycloaromatization at cryogenic temperature
Waddell, Michelle K.,Bekele, Tefsit,Lipton, Mark A.
, p. 8372 - 8377 (2007/10/03)
A series of acetoxy-substituted enyne-allenes, fused to cyclopentene and cyclohexene ring systems, were synthesized and treated with methyllithium to generate the corresponding enolates. It was found that whereas the cyclohexannulated examples underwent e
