90687-81-3Relevant articles and documents
Kinetic resolution of amines with enantiopure 3-N,N-diacylaminoquinazolin-4(3H)-ones
Al-Sehemi, Abdullah G.,Atkinson, Robert S.,Fawcett, John
, p. 257 - 274 (2007/10/03)
The title compounds (DAQs) are chiral when the two N-acyl groups are different because of the absence of rotation around the N-N bond (a chiral axis). Enantiopure DAQs have been obtained by incorporation of a chiral centre in enantiopure form either into the substituent at the Q2-position or into one of the N-acyl groups, or into both, followed by separation of diastereoisomers. This separation is unnecessary in one case because conversion of the N-monoacylaminoquinazolinone (MAQ) into the DAQ is completely diastereoselective. Neither is separation of diastereoisomers necessary with 3-[N,N-di-(S)-2-acetoxypropanoylamino]-2-diphenylmethylquinazolin-4(3H)-one 37a: this DAQ 37a has its N-N bond rendered a chiral axis by the bias in its imide moiety wholly in favour of one exo/endo conformation. The high chemoselectivity exhibited by N,N-diacetyl- or N,N-dibenzoylaminoquinazolinones in reaction with the less hindered of two secondary amines (pyrrolidine in the presence of 1 eq. of piperidine) has a stereoselective counterpart: reaction of the above enantiopure DAQs enantioselectively with racemic amines leading to kinetic resolution. Using 1 eq. of DAQ and 2 eq. of amine, both the derivatised and unreacted amine enantiomers are recovered with high enantiomeric excess (ee) (better than 90% ee in some cases). Some of the higher ees are found in the recovered amides where non-chemoselective attack on both N-acyl groups of the DAQ has occurred: from the opposite configurations of the amine component in the two amides and from the low enantiopurity of the recovered unreacted amine, reaction of each of the N-acyl groups with complementary enantiomers of the amine is occurring (parallel kinetic resolution). Although higher ees are, in general, obtained using secondary amines, high ees are obtained in some cases using 1-phenylethylamine and, in particular, amino acid esters (valine and alanine). The sense of enantioselectivity in the reactions of these DAQs with amines is controlled by the configuration of the N-N axis: replacing the Q group in an N-(S)-2-acetoxypropanoyl-N-acetyl-bearing DAQ by phthalimide, thus eliminating the N-N chiral axis, drastically reduces the level of kinetic resolution.
3-Di-[(S)-2-acetoxypropanoyl] aminoquinazolin-4(3H)-ones: Stereostructure and application in kinetic resolution of amines
Al-Sehemi, Abdullah G.,Atkinson, Robert S.,Fawcett, John,Russell, David R.
, p. 2243 - 2246 (2007/10/03)
Whereas 3-diacylaminoquinazolin-4(3H)-ones (DAQs) have been previously shown to undergo rapid exo/endo-endo/exo conformational interconversion of their imide carbonyl groups, the title DAQs are believed to exist in one single exo/endo form and consequently their N-N bonds are chiral axis: one of these DAQs, substituted with a diphenylmethyl group on the Q-2 position, reacts preferentially with one enantiomer of racemic 2-methyl-piperidine at the 2-acetoxypropanoyl imide carbonyl group (ee 94%). (C) 2000 Elsevier Science Ltd.
Stereochemical Structure-Activity Relationship of N-(2,3-Epoxypropyl)-N-(&α-methylbenzyl)benzenesulfonamide Derivatives
Yoneyama, Koichi,Ichizen, Nobumasa,Konnai, Makoto,Takematsu, Tetsuo,Ushinohama, Kazuyuki,Jikihara, Tetsuo
, p. 995 - 1000 (2007/10/02)
The absolute configuration of two assymetric centers in four stereoisomers of N-(2,3-epoxypropyl)-N-(α-methylbenzyl)benzenesulfonamide were determined and their biological activities were tested.Consequently, N--N-benzenesulfonamide was found to be the most active isomer and the stereochemistry of the benzyl position was found to be more important than that of C2 in the epoxypropyl group for biological activity.
