78018-57-2Relevant articles and documents
A new dendrimer series: synthesis, free radical scavenging and protein binding studies
Makawana, Dhaval,Singh, Man
, p. 21914 - 21932 (2020/07/03)
Tri-o-tolyl benzene-1,3,5-tricarboxylate (TOBT (T0)), tri-4-hydroxyphenyl benzene-1,3,5-tricarboxylate (THBT (T1)), and tri-3,5-dihydroxyphenyl benzene-1,3,5-tricarboxylate (TDBT (T2)), a series of 1sttier dendrimers with a common 1,3,5-benzenetricarbonyl trichloride/trimesoyl chloride (TMC) core, are reported.T0does not have any replaceable H+on its terminal phenyl group, acting as a branch.T1has one phenolic -OH at theparaposition andT2has two phenolic -OH groups at the 3 and 5 positions of each terminal phenyl group. During synthesis, these -OH groups at the terminal phenyl groups were protected throughtert-butyldimethylsilyl chloride (TBDMSCl) assisted witht-BuOK in DCM, THF, indazole, 4-dimethylaminopyridine (DMAP), and tertiary-n-butyl ammonium fluoride (TBAF). MTBDMSP (mono-tertiary butyl dimethylsilane phloroglucinol), DTBDMSP (di-tertiary butyl dimethylsilane phloroglucinol), and TTBDMSP (tri-tertiary butyl dimethylsilane phloroglucinol) were obtained with >90percent yield, and TTBDMSP phenolic derivatives (PDs) were developed to synthesizeT0,T1, andT2dendrimers by deprotecting with TBAF.T0showed superhydrophobic properties as it did not dissolve in methanol, contrary toT1andT2, but dissolved in acetone. Their structures were determined using1H and13C NMR spectroscopies, and mass spectrometry. Their scavenging activities were studied using UV-Vis spectrophotometry compared with ascorbic acid and protein binding was studied with bovine serum albumin (BSA) and lysozyme (lyso).T0exhibited exceptional optical activity contrary toT1andT2, which acted as antioxidants to scavenge free radicals.
Efficient preparation of apically substituted diamondoid derivatives
Kahl, Paul,Tkachenko, Boryslav A.,Novikovsky, Anatoliy A.,Becker, Jonathan,Dahl, Jeremy E. P.,Carlson, Robert M. K.,Fokin, Andrey A.,Schreiner, Peter R.
, p. 787 - 798 (2014/04/03)
We present an effective three-step chromatography-free sequence for the preparation of apical monohydroxy derivatives of diamantane, triamantane, and [121]tetramantane from the corresponding bis-apical diols utilizing tert-butyldimethylsilyl chloride as t
Total synthesis of (+)-α-onocerin in four steps via four-component coupling and tetracyclization steps
Mi, Yuan,Schreiber, Juerg V.,Corey
, p. 11290 - 11291 (2007/10/03)
A remarkably short (four steps, 31% overall yield) enantioselective synthesis of the structurally unique C2-symmetric tetracyclic triterpene (+)-α-onocerin (1) has been developed. The brevity of this mechanism depends on the assembly of four fragments (two molecules of a chiral epoxy ketone and two molecules of vinyllithium) to generate the chiral bis-epoxide 4 in one step, and on the efficient formation of all four carbocyclic rings in one step by cation-olefin tetracyclization. New and general methodology for the conversion of vinyl tert-butyldimethylsilyl ethers to vinyl triflates with retention of E or Z olefinic geometry also was utilized in the synthesis of 1. A short enantioselective synthesis of a non-C2-symmetric diastereomer of 1 is also described which uses the new methodology. Copyright
