74190-01-5Relevant academic research and scientific papers
Dihydrobiphenylenes through ruthenium-catalyzed [2+2+2] cycloadditions of ortho-alkenylarylacetylenes with alkynes
Garcia-Rubin, Silvia,Gonzalez-Rodriguez, Carlos,Garcia-Yebra, Cristina,Varela, Jesus A.,Esteruelas, Miguel A.,Saa, Carlos
supporting information, p. 1841 - 1844 (2014/03/21)
A new synthetic route to dihydrobiphenylenes has been developed. The process involves a mild RuII-catalyzed [2+2+2] dimerization of ortho-alkenylarylacetylenes or its more versatile variant, the Ru-catalyzed [2+2+2] cycloaddition of ortho-ethynylstyrenes with alkynes. Mechanistic aspects of this [2+2+2] cycloaddition are discussed. A new synthetic route to dihydrobiphenylenes involves a mild RuII-catalyzed [2+2+2] dimerization of ortho-alkenylarylacetylenes or its more versatile variant, the Ru-catalyzed [2+2+2] cycloaddition of ortho-ethynylstyrenes with alkynes. The mechanistic aspects of this [2+2+2] cycloaddition are also discussed. Copyright
Unexpected conversion of alkyl azides to alkyl iodides and of aryl azides to N-tert-butyl anilines
Maury, Julien,Feray, Laurence,Bertrand, Michele P.,Kapat, Ajoy,Renaud, Philippe
, p. 9606 - 9611,6 (2020/08/20)
In the presence of tert-butyl iodide, alkyl azides are converted into the corresponding iodides at room temperature, whereas, N-t-Bu anilines are obtained from aryl azides under the same experimental conditions. A mechanism is proposed to explain this unusual reactivity.
Synthesis of complex ortho-allyliodoarenes by employing the reductive iodonio-claisen rearrangement
Khatri, Hem Raj,Zhu, Jianglong
, p. 12232 - 12236 (2012/11/07)
The reductive iodonio-Claisen rearrangement (RICR), involving complex aromatic λ3-iodanes and allyltrimethylsilane, was investigated. The RICR reaction of complex substituted aromatic hypervalent iodine (III) compounds and an allylmetal partner was conducted. The anionic oxy Cope rearrangement was found to be approximately 1010 to 1017 times faster than the neutral oxy Cope rearrangement due to weakening of the adjacent C-C bond by the oxygen anion. The results also indicate that the steric and electronic nature of the aromatic λ3-iodanes is the dominant factor influencing the [3,3]-sigmatropic rearrangement reaction. The removal of tert-butyl ether protecting group by using trifluroacetic acid in dichloromethane in the presence of triisopropylsilane gives the natural product broussin in 39% yield.
Nickel-catalyzed heck-type reactions of benzyl chlorides and simple olefins
Matsubara, Ryosuke,Gutierrez, Alicia C.,Jamison, Timothy F.
supporting information; experimental part, p. 19020 - 19023 (2011/12/21)
Nickel-catalyzed intermolecular benzylation and heterobenzylation of unactivated alkenes to provide functionalized allylbenzene derivatives are described. A wide range of both the benzyl chloride and alkene coupling partners are tolerated. In contrast to analogous palladium-catalyzed variants of this process, all reactions described herein employ electronically unbiased aliphatic olefins (including ethylene), proceed at room temperature, and provide 1,1-disubstituted olefins over the more commonly observed 1,2-disubstituted olefins with very high selectivity.
Palladium-catalyzed carbonylative cyclization of 1-iodo-2-alkenylbenzenes
Negishi, Ei-Ichi,Copéret, Christophe,Ma, Shengming,Mita, Takeshi,Sugihara, Takumichi,Tour, James M.
, p. 5904 - 5918 (2007/10/03)
The Pd-catalyzed carbonylation of ω-vinyl-substituted o-iodoalkenylbenzenes 1-4 can provide up to modest yields (50-60%) of 5- and 6-membered Type I cyclic acylpalladation products, i.e., α,β-unsaturated cyclic ketones, in the absence of an external nucleophile and high yields of 5- and 6-membered Type II cyclic acylpalladation products, i.e., α- or β-((alkoxycarbonyl)methyl)substituted cyclic ketones in the presence of an alcohol, e.g., MeOH. In cases where no such processes are available, other side reactions, such as cyclic carbopalladation, polymeric acylpalladation, and trapping of acylpalladiums via esterification and other processes may become predominant. Neither smaller, i.e., 3- or 4-membered, nor 7-membered or larger cyclic ketones appear to be accessible by the reaction. In most cases, the exo-mode cyclic acylpalladation takes place exclusively. However, the cyclic acylpalladation of 3 proceeds exclusively via endo-mode cyclization to give 5-membered ketones. Substitution of one or more hydrogens in the ω-vinyl group with carbon groups has significant effects on the reaction course. Those substrates containing a 1,2-disubstituted alkenyl group in place of a vinyl group, i.e., 19-22 and 24 excluding 25, can give monomeric cyclic acylpalladation products in high yields. These results represent a major deviation from those obtained with 1 and 2. In the absence of an external nucleophile, formation of Type I cyclic acylpalladation products is, in some cases, accompanied by Type III cyclic acylpalladation involving trapping of acylpalladiums by internal enolates. In the presence of MeOH or other alcohols, Type II acylpalladation products have been obtained in respectable yields from 19-20, 23, and 24. In the presence of an alcohol, premature esterification can be a serious side reaction. However, this problem can be alleviated using i-PrOH or t-BuOH in place of MeOH in combination with appropriate solvents, typically those of lower polarity. Heteroatom-containing substituents on the ω-vinyl groups also exert significant effects on cyclic acylpalladation. Electron-donating substituents tend to lead to high yields of cyclic acylpalladation products, while electron-withdrawing alkoxycarbonyl groups conjugated with the ω-alkenyl group tend to give lower yields of cyclic acylpalladation products. With Me3Si and alkoxycarbonyl groups products of apparent endo-mode cyclic acylpalladation, i.e., naphthols, have been obtained in significant yields (25-50%). Free OH and other nucleophilic heteroatom groups can seriously interfere with cyclic acylpalladation, and they must be appropriately protected in most cases, although there are indications that acylpalladation-lactonization tandem processes similar to Type II cyclic acylpalladation might be developed.
REACTION OF ALLYLTRIMETHYLSILANE WITH AN AROMATIC COMPOUND USING HYPERVALENT ORGANOIODINE COMPOUND: A NEW ALLYLATION OF AROMATIC COMPOUNDS
Lee, Kilsung,Kim, Dae Young,Oh, Dong Young
, p. 667 - 668 (2007/10/02)
New general method for the allylation of aromatic compounds from allyltrimethylsilane utilizing the combination of iodosylbenzene and BF3 OEt2 are described, which is based upon the umpolung of allyltrimethylsilane by way of cationic allylphenyliodonium (III) salt complex as an intermediate.
Studies on the rearrangement of (trichloromethyl)carbinols to α-chloroacetic acids
Reeve, Wilkins,McKee, James R.,Brown, Robert,Lakshmanan, Sitarama,McKee, Gertrude A.
, p. 485 - 493 (2007/10/02)
Phenyl(trichloromethyl)carbinol undergoes an unimolecular, predominantly intramolecular conversion into potassium α-chlorophenylacetate on stirring with 10percent aqueous potassium hydroxide at 0 deg C for several days.Besides providing an interesting example of a 1-2 chlorine shift, the reaction is of potential importance for the synthesis of α-chloro acids.The study of a variety of (trichloromethyl)carbinols shows the reaction is general for secondary (trichloromethyl)carbinols as well as trichloroethanol.The mechanism of the reaction involves the preliminary formation of an epoxide.Several mechanisms are considered for the conversion of the epoxide to the α-chloroacetate anion, but none accounts for all of the experimental facts.Tertiary carbinols break down at the epoxide stage into a ketone and carbon monoxide.
