Synthesis of Novel Amino Acids and Dehydroamino Acids Containing the Benzo[b]thiophene Moiety
作者:Ana S. Abreu、Natália O. Silva、Paula M. T. Ferreira、Maria-João R. P. Queiroz
DOI:10.1002/ejoc.200390212
日期:2003.4
Several novel amino acids and dehydroamino acids containing the benzo[b]thiophene moiety were prepared by Michael addition or sequential Michael addition and palladium-catalyzed C−C or C−N cross couplings. The substrates for Michael addition were the methyl esters of N,N-bis(tert-butyloxycarbonyl)dehydroalanine [Boc2−ΔAla−OMe] and N-(4-toluenesulfonyl)-N-(tert-butyloxycarbonyl)dehydroalanine [Tos−ΔAla(N-Boc)−OMe]
Synthesis of pure stereoisomers of benzo[b]thienyl dehydrophenylalanines by Suzuki cross-coupling. Preliminary studies of antimicrobial activity
作者:Ana S. Abreu、Paula M.T. Ferreira、Luís S. Monteiro、Maria-João R.P. Queiroz、Isabel C.F.R. Ferreira、Ricardo C. Calhelha、Letícia M. Estevinho
DOI:10.1016/j.tet.2004.09.107
日期:2004.12
benzo[b]thienyldehydrophenylalanines were synthesized from pure stereoisomers of the methyl ester of N-(tert-butoxycarbonyl)-β-bromodehydrophenylalanine as an extension of our previously reported method for the synthesis of dehydrotryptophan analogues to dehydrophenylalanine derivatives. The latter were obtained in high yields by N-deprotection and bromination of N,N-bis-(tert-butoxycarbonyl)-(Z)-dehydrophenylalanine
由N-(叔丁氧羰基)-β-溴代氢苯丙氨酸甲酯的纯立体异构体合成了几种苯并[ b ]噻吩基脱氢苯丙氨酸,作为我们先前报道的将脱氢色氨酸类似物合成为脱氢苯丙氨酸衍生物的方法的扩展。后者通过TFA和NBS通过N-脱保护和溴化N,N-双-(叔丁氧基羰基)-(Z)-脱氢苯丙氨酸以高收率获得。这是分两个步骤进行的,也可能是一个罐的操作,从而产生不同的E / Z比率。这些化合物在铃木交叉偶联条件下[Pd(PPh 3)4,Na 2 CO 3,DME / H 2 O]与几种硼苯并[ b ]噻吩基酸以良好或高收率偶联,保持了起始原料的立体化学。当硼酸在苯并[ b ]噻吩的7位上并且与溴化脱氢苯丙氨酸的E异构体一起时,可获得最佳收率。在某些情况下,可以通过将Pd源更改为PdCl 2(PPh 3)2来提高较低的产量。制备了模型二肽偶联苯并[ b]噻吩基脱氢苯基丙氨酸与丙氨酸的甲酯。对获得的β,β-二芳基脱氢丙氨酸
Synthesis and intramolecular cyclization of novel β,β-bis-(benzo[b]thienyl)dehydroalanine derivatives
作者:Ana S. Abreu、Natália O. Silva、Paula M.T. Ferreira、Maria-João R.P. Queiroz
DOI:10.1016/s0040-4039(03)00564-1
日期:2003.4
β-dibromodehydroalanine was obtained in a one-pot procedure from bis-(N-tert-butyloxycarbonyl)dehydroalanine. The former was reacted with several boronic benzo[b]thiophene acids under Suzuki cross coupling conditions, to give new β,β-bis-(benzo[b]thienyl)dehydroalanines in high yields. These compounds were cyclized to pyrrole derivatives by treatment with Pd(OAc)2 and Cu(OAc)2 in DMF.
的甲基酯叔丁氧基羰基β,被一个一锅法中,从双- (β获得-dibromodehydroalanine ñ -叔脱氢丙氨酸丁氧基羰)。前者在铃木交叉偶联条件下与几种硼苯并[ b ]噻吩酸反应,以高收率得到新的β,β-双-(苯并[ b ]噻吩基)脱氢丙氨酸。通过在DMF中用Pd(OAc)2和Cu(OAc)2处理,将这些化合物环化为吡咯衍生物。
Synthesis Using Suzuki Cross Couplings of Sulfur Analogues of Dehydrotryptophan with a Definite Stereochemistry
作者:Natália O. Silva、Ana S. Abreu、Paula M. T. Ferreira、Luís S. Monteiro、Maria-João R. P. Queiroz
(40−80%) by Suzuki cross coupling [Pd(PPh3)4, Na2CO3 or NaHCO3, DME/H2O, 90 °C] of several benzo[b]thiophene boronic acids with the methyl esters of N-tert-butyloxycarbonyl-β-bromodehydroalanine [Boc-ΔAla(β-Br)-OMe] or N-tert-butyloxycarbonyl-β-bromodehydroaminobutyric acid [Boc-ΔAbu(β-Br)-OMe]. The β-bromodehydroamino acid precursors 2 were, in turn, synthesized in high yields from the corresponding N,N-diacyldehydroamino
Newβ,β-Bis(benzo[b]thienyl)dehydroalanine Derivatives: Synthesis and Cyclization
作者:Ana S. Abreu、Natália O. Silva、Paula M. T. Ferreira、Maria-João R. P. Queiroz、Mariano Venanzi
DOI:10.1002/ejoc.200300394
日期:2003.12
triethylamine. This compound was then used in Suzuki cross-coupling reactions with several (benzo[b]thienyl)boronic acids to give the corresponding β,β-bis(benzo[b]thienyl)dehydroalanine derivatives in good to high yields (55−90 %). After several experiments, the best conditions were shown to be: (benzo[b]thienyl)boronic acid (5 equiv.), [Pd(PPh)2Cl2] (20 mol %), Na2CO3 (4 equiv.) in DME/H2O (10:1). The