New Chiral Derivatizing Agents: Convenient Determination of Absolute Configurations of Free Amino Acids by <sup>1</sup>H NMR
作者:Michio Kurosu、Kai Li
DOI:10.1021/ol8028719
日期:2009.2.19
The chiral carbonate reagents 5 allow for the direct and unambiguous determination of the absolute configurations of a wide range of free amino acids using 1H NMR. By using a ∼3:1 mixture of (S)-5 and (R)-5, absolute configurations of the corresponding carbamates are determined by only analyzing the nitrogen protons.
手性碳酸酯试剂5允许使用1 H NMR直接和明确地确定各种游离氨基酸的绝对构型。通过使用〜(S)-5和(R)-5的〜3:1混合物,仅通过分析氮质子即可确定相应氨基甲酸酯的绝对构型。
Polymer-Supported (2,6-Dichloro- 4-alkoxyphenyl)(2,4-dichlorophenyl)methanol: A New Linker for Solid-Phase Organic Synthesis
作者:Michio Kurosu、Kallolmay Biswas、Dean C. Crick
DOI:10.1021/ol070150f
日期:2007.3.1
amines, alcohols, and phenols, and are stable to Bronsted and Lewis acids, Bronsted bases, and a wide variety of nucleophiles. However, the HTPM linkers can conveniently be cleaved by the solvolyticdisplacementreactions with 20% TFA. [structure: see text]
An acid- and base-stable protectinggroup for carboxylic acids is described. The esters of (2,6-dichloro-4-methoxyphenyl)(2,4-dichlorophenyl)methanol are stable to Bronsted and Lewis acids, Bronsted bases, and a wide variety of nucleophiles; however, the esters can be conveniently deprotected by a solvolytic displacement reaction with 20% trifluoroacetic acid.
High-Throughput Synthesis of Substituted Hydrazine Derivatives
作者:Michio Kurosu、Prabagaran Narayanasamy、Dean C. Crick
DOI:10.3987/com-07-s(u)14
日期:——
Regioselective alkylations of the hydrazine derivatives are achieved by using the (2,6-dichloro-4-methoxyphenyl)(2,4-dichlorophenyl)methoxycarboxyl resin. High-throughput synthesis of monosubstituted and 1,1-disubstituted hydrazine building blocks is described.