One-Pot Synthesis Of Chiral Disulfides & Diselenides From α-Amino Acids Mediated By Ammonium Tetrathiomolybdate In Water
Electronic Theses of Indian Institute of Science
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Title |
One-Pot Synthesis Of Chiral Disulfides & Diselenides From α-Amino Acids Mediated By Ammonium Tetrathiomolybdate In Water
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Creator |
Navin, V
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Subject |
Organic Chemistry
Tetrathiomolybdate Sulfur Compounds Amino Acids Carboxylic Acids Selinide Compounds Sulfur Transfer Thiocyanate Reductive Dimerization Selenocyante Thiocyanato Carboxylic Acids Disulfides Diselenides |
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Description |
We have described herein a convenient one-pot synthesis of lisulfides/diselenides from a-amino acids mediated by ammonium etrathiomolybdate in water. (Figure 1) (Figure) Figure 1 Transformation of α-amino acids into the corresponding tiiocyanates/selenocyanates/disulfides/diselenides Halo-de-amination of a-amino acids using HBr/NaNCte followed by treatment with ammonium tetrathiomolybdate (NH4)2]VloS4 jLb provided a general route for the the one-pot synthesis of chiral a,a' bis (dithio) carboxylic acids (Figure 1, 2b). The yields were moderate, limited mainly the moderate conversion of a-amino acids into the corresponding chiral a-bromides. It was possible to synthesize the 2-thiocyanto carboxylic acids from the corresponding a-amino acids by a similar strategy. Thus diazotization in the presence of KSCN yielded in the chiral 2-thiocyanto carboxylic acids in moderate yields (Figure 1, 3). Thiocyanato-de-amination thus afforded the thiocyanates which when treated with JJD provided the chiral disulfides (Figure 1, 4a). We could thus synthesize both enantiomers of the disulfide from a single enantiomer of the starting a-amino acid. (Figure 1, 4a,4b) Using a similar strategy we have also demonstrated an efficient method for the synthesis of chiral selenocyanates starting from a-amino acids, using selenocyanate anion as the nucleophile (Figure 1, 5). It is possible to demonstrate a one-pot synthesis of chiral diselenides by reductive coupling of selenocyanates using JJb. (Figure 1, 6) (for figure see the pdf file) |
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Publisher |
Indian Institute of Science
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Contributor |
Chandrasekaran, Srinivasan
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Date |
2007-03-27T04:16:47Z
2007-03-27T04:16:47Z 2007-03-27T04:16:47Z 2001-05 |
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Type |
Electronic Thesis and Dissertation
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Format |
2066890 bytes
application/pdf |
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Identifier |
http://hdl.handle.net/2005/268
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Language |
en
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Rights |
I grant Indian Institute of Science the right to archive and to make available my thesis or dissertation in whole or in part in all forms of media, now hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation.
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