53165-22-3Relevant academic research and scientific papers
Palladium-catalyzed intramolecular aryl amination reaction: An expeditious approach to the synthesis of chiral benzodiazocine derivatives
Adhikary, Nirmal Das,Chattopadhyay, Partha
experimental part, p. 1754 - 1762 (2010/06/15)
A palladium-catalyzed method for intramolecular amination of aryl bromides and iodides has been developed employing different bulky biaryl phosphanes as ligands and toluene as solvent. A variety of electron-rich aryl halide substrates have been aminated b
Titanium reagents for the synthesis of 2-substituted benzo[b]thiophenes on the solid phase
Roberts, Christine F.,Hartley, Richard C.
, p. 6145 - 6148 (2007/10/03)
Titanium(IV) benzylidenes (Schrock carbenes) bearing a masked sulfur nucleophile in the ortho position were generated from thioacetals with use of low-valent titanocene complex Cp2Ti[P(OEt)3]2 and alkylidenated Merrifield resin-bound esters to give enol ethers. Treatment of the resin-bound enol ethers with a 5:5:90 mixture of TFA, TFAA, and dichloromethane led to cleavage from resin, removal of the tert- butyldimethylsilyl (TBDMS) protecting group, and concomitant cyclization to complete the traceless solid-phase synthesis (SPS) of benzothiophenes. Switching the nature of the linker from acid-stable to acid-sensitive ensured good purity.
Synthesis of 2-substituted benzofurans and indoles using functionalized titanium benzylidene reagents on solid phase
Macleod, Calum,McKiernan, Gordon J.,Guthrie, Emma J.,Farrugia, Louis J.,Hamprecht, Dieter W.,Macritchie, Jackie,Hartley, Richard C.
, p. 387 - 401 (2007/10/03)
Titanium(IV) benzylidenes bearing a masked oxygen or nitrogen nucleophile in the ortho position were generated from thioacetals, using low-valent titanocene complex, Cp2Ti[P(OEt)3]2. Methylene acetal, alkyl ether, silyl ether, fluoro, tertiary amino, and N-alkyl, N-benzyl, N-prenyl, and N-silyl tert-butyl carbamate groups were tolerated in the titanium alkylidene reagents (Schrock carbenes). Aryl-chlorine bonds were stable to the titanium benzylidene functionality, but there was poor chemoselectivity for the reduction of the thioacetal in the presence of an aryl chloride. The titanium benzylidenes converted Merrifield and Wang resin-bound esters into enol ethers. The oxygen nucleophile was masked as a TMS ether, and when the resin-bound enol ethers bearing this ortho substituent were treated with 1% TFA in dichloromethane, benzofurans were released from resin in high yields. The chameleon catch strategy ensured excellent purity. In a similar way, N-alkylated and N-silylated tert-butyl carbamates were used for the synthesis of N-alkyl and N-Boc indoles, respectively. These traceless solid-phase syntheses of heterocycles are believed to involve post-cleavage modification rather than cyclative termination.
Novel functionalized titanium(IV) benzylidenes for the traceless solid-phase synthesis of indoles
Macleod, Calum,Hartley, Richard C.,Hamprecht, Dieter W.
, p. 75 - 78 (2007/10/03)
(matrix presented) Titanium(IV) benzylidenes bearing a masked nitrogen nucleophile in the ortho position converted Merrifield resin-bound esters into enol ethers. An unusual nitrogen protecting group, N-silylated tert-butyl carbamate, was employed. One percent TFA released N-Boc indoles in high yield and purity. N-Methyl indoles were also prepared. Cyclative termination was not required to release the chameleon catch. The first example of a carbonyl group within a titanium alkylidene reagent is reported.
Thermal Reaction of Phenylnitrene with Sulfides
Benati, Luisa,Grossi, Mario,Montevecchi, P. Carlo,Spagnolo, Piero
, p. 763 - 765 (2007/10/02)
Thermolysis of phenyl azide in the presence of sulfides bearing α-hydrogen atoms leads to the formation of significant amounts of 2-substituted anilines, presumably by Sommelet-Hauser type rearrangement of the intermediate N-phenylsulfimides.
