Papers by Woraluk Mansawat
Synlett
C 2-Symmetrical chiral amino alcohol ligands with a central thiophene moiety were shown to be eff... more C 2-Symmetrical chiral amino alcohol ligands with a central thiophene moiety were shown to be effective in combination with CuCl2 for the asymmetric acylation of dl-hydrobenzoins. In contrast to previously developed chiral ligands, readily available acetyl chloride and acetic anhydride can be used as reagents, in addition to benzoyl chloride, giving rise to the corresponding monoacylated products in up to 99% ee (S = 532).
Tetrahedron, 2009
A practical procedure for catalytic asymmetric synthesis of optically active arylglycine derivati... more A practical procedure for catalytic asymmetric synthesis of optically active arylglycine derivatives via optically active α-aminonitriles has been developed. The N-benzhydryl α-arylaminonitrile intermediates were prepared in excellent yield (89–99%) and enantiomeric purity (96 to >98% ee) by enantioselective cyanation of aldimines with TMSCN/iPrOH in the presence of 2.5mol% of an easily prepared Ti/chiral amino alcohol complex at 0°C, without requiring
ChemInform, 2003
An enantioselective Strecker synthesis employing novel chiral titanium complex catalysts derived ... more An enantioselective Strecker synthesis employing novel chiral titanium complex catalysts derived from structurally simple chiral N-salicyl-β-amino alcohols is described. Reactions of N-benzylidenebenzylamine with trimethylsilyl cyanide in the presence of the catalyst (10 mol%) gave the corresponding α-aminonitrile in good to excellent yields, along with relatively high enantioselectivity (up to 86% ee). Similar reactions with various imines derived from aromatic aldehydes
Tetrahedron Letters, 2007
Thiolated amino-alcohols have been synthesized and evaluated as a potential new class of chiral l... more Thiolated amino-alcohols have been synthesized and evaluated as a potential new class of chiral ligands for copper-catalyzed nitro-aldol reactions. The model nitro-aldol reaction took place smoothly at ambient temperature in the presence of catalytic amounts (5–15mol%) of the ligands and copper(II) acetate to afford the nitro-aldol product in good to excellent yield without accompanying dehydration. Amino-alcohol ligands bearing N-(2-alkylthio)benzyl substituents
Tetrahedron, 2004
A Highly Enantioselective Strecker Reaction Catalyzed by Titanium-N-salicyl-β-aminoalcohol Comple... more A Highly Enantioselective Strecker Reaction Catalyzed by Titanium-N-salicyl-β-aminoalcohol Complexes.
Organic Letters, 2012
The effect of ring size of four- to six-membered cyclic β-amino acid on the hybridization propert... more The effect of ring size of four- to six-membered cyclic β-amino acid on the hybridization properties of pyrrolidinyl peptide nucleic acid with an alternating α/β peptide backbone is reported. The cyclobutane derivatives (acbcPNA) show the highest T(m) and excellent specificity with cDNA and RNA.
Organic & Biomolecular Chemistry, 2013
Hypoxanthine is an unnatural base that can potentially pair with all natural nucleobases. While h... more Hypoxanthine is an unnatural base that can potentially pair with all natural nucleobases. While hypoxanthine in DNA exhibits marginal preference for pairing with cytosine (C), little is known about its pairing behavior in other DNA analogues. In this study, we synthesized a hypoxanthine-containing monomer and incorporated it into pyrrolidinyl peptide nucleic acid with α/β-peptide backbone derived from D-prolyl-(1S,2S)-2-aminocyclopentanecarboxylic acid (acpcPNA). DNA binding studies clearly revealed that hypoxanthine in acpcPNA behaves like G-analogue because it can specifically form a stable base pair with dC in DNA. The ability to replace G by hypoxanthine without affecting the base pairing properties of acpcPNA can solve a number of problems associated with G-rich acpcPNA including difficult synthesis, formation of secondary structures and fluorescence quenching.
Tetrahedron, 2012
ABSTRACT Pyrene as well as other aromatic hydrocarbons could be successfully incorporated in to p... more ABSTRACT Pyrene as well as other aromatic hydrocarbons could be successfully incorporated in to pyrrolidinyl peptide nucleic acid bearing a D-prolyl-2-aminocyclopentane carboxylic acid backbone (acpcPNA) as a base surrogate via a triazole linker employing Cu- catalyzed alkyne-azide cycloaddition (click chemistry). The labeling can be performed via a pre-clicked pyrene monomer or by post-synthetic modification of azide-containing acp cPNA on solid support. Thermal denaturation experiments suggested that the pyrene-triazole unit can be have as a universal base in the acpcPNA system. The mode of base-pairing has been proposed based on molecular dynamics simulations. Importantly, the fluorescence spectra of the pyrene-labeled single stranded acpcPNA and its hybrid with DNA are quite different. The ratio of emission s at 380 and 460 nm changed significantly (up to a factor of 7) upon hybrid formation with complementary DNA.
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Papers by Woraluk Mansawat