789-24-2Relevant articles and documents
Gilman,Morton
, p. 2514 (1948)
Decatungstate-Photocatalyzed Radical Addition of 9-Substituted Fluorenes to [60]Fullerene: A Mechanistic Approach
Malliaros, Nikitas G.,Orfanopoulos, Michael
supporting information, p. 4846 - 4850 (2021/09/20)
An innovative, efficient, regioselective functionalization of C60 with 9H-fluorenes has been disclosed. This efficient photochemical approach uses certain fluorenyl radicals in 9-position deriving from fluorenes through a hydrogen-atom transfer (HAT) process mediated by tetrabutylammoniumdecatungstate [(n-Bu4N)4W10O32]. The single addition of these fluorenyl radicals to C60 proceeded to produce [60]fullerene-fluorene dyads in a single step. The scope and mechanism of this new reaction have been examined. The primary kinetic isotope effect measurements signify the presence of a stepwise mechanism in which the C?H (D) bond scission is the rate-limiting step of the reaction.
Transition-Metal-Free Synthesis of Polyfunctional Triarylmethanes and 1,1-Diarylalkanes by Sequential Cross-Coupling of Benzal Diacetates with Organozinc Reagents
Wei, Baosheng,Ren, Qianyi,Bein, Thomas,Knochel, Paul
, p. 10409 - 10414 (2021/03/26)
A variety of functionalized triarylmethane and 1,1-diarylalkane derivatives were prepared via a transition-metal-free, one-pot and two-step procedure, involving the reaction of various benzal diacetates with organozinc reagents. A sequential cross-coupling is enabled by changing the solvent from THF to toluene, and a two-step SN1-type mechanism was proposed and evidenced by experimental studies. The synthetic utility of the method is further demonstrated by the synthesis of several biologically relevant molecules, such as an anti-tuberculosis agent, an anti-breast cancer agent, a precursor of a sphingosine-1-phosphate (S1P) receptor modulator, and a FLAP inhibitor.
Mild, Rapid, and Chemoselective Procedure for the Introduction of the 9-Phenyl-9-fluorenyl Protecting Group into Amines, Acids, Alcohols, Sulfonamides, Amides, and Thiols
Soley, Jacob,Taylor, Scott D.
, (2020/02/04)
The 9-phenyl-9-fluorenyl (PhF) group has been used as an Nα protecting group of amino acids and their derivatives mainly as a result of its ability to prevent racemization. However, installing this group using the standard protocol, which employs 9-bromo-9-phenylfluorene/K3PO4/Pb(NO3)2, often takes days and yields can be variable. Here, we demonstrate that the PhF group can be introduced into the amino group of Weinreb's amides and methyl esters of amino acids, as well as into alcohols and carboxylic acids, rapidly and in excellent yields, using 9-chloro-9-phenylfluorene (PhFCl)/N-methylmorpholine (NMM)/AgNO3. Nα-PhF-protected amino acids can be prepared from unprotected α-amino acids, rapidly and often in near quantitative yields, by treatment with N,O-bis(trimethylsilyl)acetamide (BSA) and then PhFCl/NMM/AgNO3. Primary alcohols can be protected with the PhF group in the presence of secondary alcohols in moderate yield. Using PhFCl/AgNO3, a primary alcohol can be protected in good yield in the presence of a primary ammonium salt or a carboxylic acid. Primary sulfonamides and amides can be protected in moderate to good yields using phenylfluorenyl alcohol (PhFOH)/BF3·OEt2/K3PO4, while thiols can be protected in good to excellent yield using PhFOH/BF3·OEt2 even in the presence of a carboxylic acid or primary ammonium group.
