- Enantioselective Friedel-Crafts reactions between phenols and N-tosylaldimines catalyzed by a leucine-derived bifunctional catalyst
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Enantioselective Friedel-Crafts reactions between phenols and N-tosylaldimines were developed using a bifunctional catalyst readily prepared from l-leucine. The chiral benzylic amine products were obtained in high yields (up to 96% yield) and good to high enantiomeric excesses (up to 95% ee).
- Li, Guo-Xing,Qu, Jin
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supporting information; experimental part
p. 5518 - 5520
(2012/07/01)
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- Trimethylsilyl trifluoromethanesulfonate (TMSOTf) assisted facile deprotection of N,O-acetonides
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(Chemical Equation Presented) Employing TMSOTf as an easily available reagent, we have developed a mild and efficient method for the deprotection of both terminal and internal N,O-acetonide functionalities. Various regularly used protecting groups and com
- Poon, Kevin W. C.,Lovell, Kimberly M.,Dresner, Kendra N.,Datta, Apurba
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p. 752 - 755
(2008/09/18)
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- Synthesis and evaluation of arylaminoethyl amides as noncovalent inhibitors of cathepsin S. Part 3: Heterocyclic P3
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A series of Nα-2-benzoxazolyl-α-amino acid-(arylaminoethyl)amides were identified as potent, selective, and noncovalent inhibitors of cathepsin S. Structure-activity relationships including strategies for modulating the selectivities among cathepsins S, K, and L, and in vivo pharmacokinetics are discussed. A X-ray structure of compound 3 bound to the active site of cathepsin S is also reported.
- Tully, David C.,Liu, Hong,Alper, Phil B.,Chatterjee, Arnab K.,Epple, Robert,Roberts, Michael J.,Williams, Jennifer A.,Nguyen, Khanhlinh T.,Woodmansee, David H.,Tumanut, Christine,Li, Jun,Spraggon, Glen,Chang, Jonathan,Tuntland, Tove,Harris, Jennifer L.,Karanewsky, Donald S.
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p. 1975 - 1980
(2007/10/03)
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- Convenient preparation of O-benzyl-N-Cbz-D-serinol, an intermediate in β-hydroxy-α-amino acid synthesis
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A convenient preparation of (2S)-3-benzyloxy-2-[(benzyloxycarbonyl)amino]propanol (2) in 52% yield, employing cheap L-serine as starting material, is described. Conversion of 2 into methyl (2Z,4R)-5-benzyloxy-4-[(benzyloxycarbonyl)amino]pent-2-enoate (1) is reported.
- Monache,Di Giovanni,Maggio,Misiti,Zappia
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p. 1155 - 1158
(2007/10/02)
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- Synthesis and platelet-activating factor (PAF)-antagonistic activities of trisubstituted piperazine derivatives
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2- or 3-Substituted 1-(2,3-dimethoxy-6,7-dihydro-5H-benzocyclobepten-8- ylcarbonyl)-4-(3,4,5-trimethoxybenzoyl)- and 4-(3,4,5- trimethoxybenzyl)piperazines (2a - s, 3a, b) were prepared and evaluated for antagonistic activities against platelet-activating
- Fukushi,Mabuchi,Terashita,Nishikawa,Sugihara
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p. 551 - 559
(2007/10/02)
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- Pinacol cross coupling of 2-[N-(alkoxycarbonyl)amino] aldehydes and aliphatic aldehydes by [V2Cl3(THF)6]2[Zn2Cl 6]. Synthesis of syn,syn-3-[N-(alkoxycarbonyl)amino] 1,2-diols
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Slow addition of 2-[N-(alkoxycarbonyl)amino] aldehydes to mixtures of [V2Cl3(THF)6]2[Zn2Cl 6] and aliphatic aldehydes gave syn,syn-3-[N-(alkoxycarbonyl)amino] 1,2-diols in good yield and high enantiomeric purity (>99:1). The alkyl group of the N-alkoxycarbonyl was shown to influence the yield: Me > allyl > Bn > t-Bu. Only the syn,syn diastereomer was observed (>20:1), except with N-Cbz-alaninal (10:1:1), O-benzyl-N-Cbz-serinal (7:1), and N-Cbz-prolinal (5:1 to 12:1). A new serinai derivative, N-Cbz-O-TBS-serinal, was cross coupled with n-pentadecanal to give a derivative of xylo-D-C18-phytosphingosine.
- Konradi, Andrei W.,Kemp, Scott J.,Pedersen, Steven F.
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p. 1316 - 1323
(2007/10/02)
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