Chemistry of novel compounds with multifunctional carbon structure. 9. Molecular design, synthetic studies, and NMR investigation of several efficient chiral derivatizing reagents which give very large 19F NMR .DELTA..delta. values in enantiomeric excess determination
摘要:
In order to develop efficient ee-determining reagents potentially superior to MTPA (1), some multifunctional compounds 2-5 were rationally designed. From NMR investigations of the analogous diastereomeric derivatives it was found that the chemical shift differences for each pair of diastereomers (DELTAdelta values) for CFPA derivatives 5d-f were approximately five times greater in F-19 NMR spectra and two times greater in H-1 NMR spectra than those of 1d-f. Synthesis of the optically pure CFPA, (-)-5a and (+)-5a, was achieved by nitrosation of each diastereomer of the optically active N-(1-phenylethyl)amides, 5f(M) and 5f(L), followed by thermal decomposition. Various derivatives were prepared by the condensation of 5b and lb with alcohol and amine nucleophiles, and both DELTAdelta(F) and DELTAdelta(H) Values were obtained for each compound. The CFPA derivatives 5d-m have proven to be significantly superior for ee determinations when compared to the corresponding MTPA derivatives 1d-m, particularly in compounds having remotely disposed chiral centers.
A decisive step forward: A one-step fluorination on modified cinchona alkaloids produced a new range of enantiopure fluorinating agents that display high enantioselectivities in electrophilicfluorination. The first enantioselective synthesis of N-protected α-fluorophenylglycine derivatives was achieved with an enantiomeric excess up to 94 % [Eq. (a); R=Et, CN; HMDS=hexamethyldisilazanide].
向前迈出了决定性的一步:在修饰的金鸡纳生物碱上进行一步氟化,产生了一系列新的对映纯氟化剂,它们在亲电氟化中显示出高对映选择性。N-保护的α-氟苯基甘氨酸衍生物的首次对映选择性合成的对映体过量最高为94%。(一种); R = Et,CN;HMDS =六甲基二硅氮杂]。
CHIRAL FLUORINATING REAGENTS
申请人:ISIS INNOVATION LIMITED
公开号:US20150284401A1
公开(公告)日:2015-10-08
This invention relates to fluorinating agents and, more particularly, to chiral non-racemic fluorinating agents useful for enantioselective fluorination, as well as to their synthesis and use and other subject matter. The fluorinating agents are based on a substituted 1,4-diazabicyclo[2.2.2]octane (DABCO) skeleton and provide electrophillic fluorine enantioselectively.
[EN] CHIRAL FLUORINATING REAGENTS<br/>[FR] RÉACTIFS DE FLUORATION CHIRAUX
申请人:ISIS INNOVATION
公开号:WO2014068341A2
公开(公告)日:2014-05-08
This invention relates to fluorinating agents and, more particularly, to chiral non-racemic fluorinating agents useful for enantioselective fluorination, as well as to their synthesis and use and other subject matter. The fluorinating agents are based on a substituted 1,4-diazabicyclo[2.2.2]octane (DABCO) skeleton and provide electrophillic fluorine enantioselectively.
Chemistry of novel compounds with multifunctional carbon structure. 9. Molecular design, synthetic studies, and NMR investigation of several efficient chiral derivatizing reagents which give very large 19F NMR .DELTA..delta. values in enantiomeric excess determination
In order to develop efficient ee-determining reagents potentially superior to MTPA (1), some multifunctional compounds 2-5 were rationally designed. From NMR investigations of the analogous diastereomeric derivatives it was found that the chemical shift differences for each pair of diastereomers (DELTAdelta values) for CFPA derivatives 5d-f were approximately five times greater in F-19 NMR spectra and two times greater in H-1 NMR spectra than those of 1d-f. Synthesis of the optically pure CFPA, (-)-5a and (+)-5a, was achieved by nitrosation of each diastereomer of the optically active N-(1-phenylethyl)amides, 5f(M) and 5f(L), followed by thermal decomposition. Various derivatives were prepared by the condensation of 5b and lb with alcohol and amine nucleophiles, and both DELTAdelta(F) and DELTAdelta(H) Values were obtained for each compound. The CFPA derivatives 5d-m have proven to be significantly superior for ee determinations when compared to the corresponding MTPA derivatives 1d-m, particularly in compounds having remotely disposed chiral centers.