33776-38-4Relevant academic research and scientific papers
Benzylic C?H Functionalisation by [Et3SiH+KOtBu] leads to Radical Rearrangements in o-tolyl Aryl Ethers, Amines and Sulfides
Arokianathar, Jude N.,Kolodziejczak, Krystian,Bugden, Frances E.,Clark, Kenneth F.,Tuttle, Tell,Murphy, John A.
supporting information, p. 2260 - 2267 (2020/05/06)
Reaction of Et3SiH+KOtBu with diaryl ethers, sulfides and amines that feature an ortho alkyl group leads to rearrangement products. The rearrangements arise from formation of benzyl radicals, likely formed through hydrogen atom abstraction by triethylsilyl radicals. The rearrangements involve cyclisation of the benzyl radical onto the partner arene, which, from computation, is the rate determining step. In the case of diaryl ethers, Truce-Smiles rearrangements arise from radical cyclisations to form 5-membered rings, but for diarylamines, cyclisations to form dihydroacridines are observed. (Figure presented.).
Rhenium- and manganese-catalyzed synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes
Kuninobu, Yoichiro,Nishi, Mitsumi,Kawata, Atsushi,Takata, Hisatsugu,Hanatani, Yumi,Salprima Yudha,Iwai, Aya,Takai, Kazuhiko
experimental part, p. 334 - 341 (2010/03/30)
(Chemical Equation Presented) We have succeeded in the development of three approaches to the synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes. The first approach is a manganese-catalyzed [2+2+2] cycloaddition between 1,3-dicarbonyl compounds, which have no substituents at the active methylene moiety, and terminal alkynes. This reaction proceeds with high regioselectivity when aryl acetylenes are employed as the alkyne component. The second approach is a rhenium- or manganese-catalyzed formal [2+1+2+1] cycloaddition between β-keto esters and two kinds of alkynes. In this reaction, the aromatic compounds are obtained by the following reaction sequence: (1) insertion of the first alkyne into a carbon-carbon single bond of a β-keto ester, (2) formation of 2-pyranones via intramolecular cyclization with the elimination of ethanol, and (3) Diels-Alder reaction between the formed 2-pyranone and the second alkyne. This reaction provides multisubstituted aromatic compounds in a regioselective manner. The third approach is a rheniumcatalyzed formal [2+2+1+1] cycloaddition reaction from two 1,3-diketones and one alkyne. In this reaction, the aromatic skeleton is constructed from three carbons of the first 1,3-diketone, two carbons of the alkyne, and one carbon of the second 1,3-diketone. 2009 American Chemical Society.
Manganese-catalyzed construction of tetrasubstituted benzenes from 1,3-dicarbonyl compounds and terminal acetylenes
Kuninobu, Yoichiro,Nishi, Mitsumi,Yudha, Salprima S.,Takai, Kazuhiko
, p. 3009 - 3011,3 (2020/08/31)
(Chemical Equation Presented) Treatment of β-keto esters with terminal acetylenes in the presence of a catalytic amount of a manganese complex, MnBr(CO)5, and molecular sieves, gave multisubstituted aromatic compounds in good to excellent yields. This reaction employs [2 + 2 + 2] cycloaddition of β-keto esters and 2 equiv of terminal acetylenes with dehydration. In the case of a 1,3-diketone, the corresponding acetophenone derivative and its deacylated compound can be synthesized selectively.
Photochemistry of 2,5,7,7-Tetraphenyl-7-boratabicyclohepta-2,4-diene (a Boratanorcaradiene Anion): No Evidence for Diphenylborene Anion
Boyatzis, Stamatis,Wilkey, John D.,Schuster, Gary B.
, p. 4537 - 4544 (2007/10/02)
Irradiation of 2,5,7,7-tetraphenyl-7-boratabicyclohepta-2,4-diene anion (1, a boratanorcaradiene, as its potassium or tetramethylammonium salt) with UV light leads to formation of p-terphenyl in high yield.This observation led us to consider the possibility that diphenylborene anion (Ph2B-, an analogue of diphenylcarbene) might also be formed in this reaction.We designed and carried out a series of spectroscopic and chemical experiments to detect and characterize the borene.None of these experiments provides evidence for the formation of diphenylborene from this reaction.We suggest that the formation of p-terphenyl from the photolysis of 1 is initiated by an electron-transfer (photoionization) process.We also reexamined experiments reported earlier that were claimed to show that diphenylborene is formed from the irraditation or overirradiation of tetraphenylborate.Each of these experiments is ambiguous and cannot be relied upon to demonstrate the formation of the borene by this route.
