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http://hdl.handle.net/11375/17280
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DC Field | Value | Language |
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dc.contributor.advisor | McNulty, Jim | - |
dc.contributor.author | Das, Priyabrata | - |
dc.date.accessioned | 2015-05-11T17:35:30Z | - |
dc.date.available | 2015-05-11T17:35:30Z | - |
dc.date.issued | 2009-08 | - |
dc.identifier.uri | http://hdl.handle.net/11375/17280 | - |
dc.description.abstract | An efficient, stereoselective method for the synthesis of α-phosphonoenamines based on a modified Peterson olefination was developed. The carbanion derived from Diethyl 1-dimethylamino-1-trimethylsilylmethanophosphonate reacted with aromatic or aliphatic aldehydes selectively eliminating in Peterson fashion to deliver functionally rich α-phosphonoenamines. A highly efficient method was developed for the one-carbon homologation of aldehydes to carboxylic acid derivatives employing the reaction of a 1, 1-bis-dimethylphosphonate derivative with the aldehyde and controlled acid hydrolysis of the derived α-phosphonoenamine intermediate. The reaction of bis(trimethylsilyl)chloromethane with s-BuLi was found to proceed via transmetallation rather than deprotonation yielding the nucleophilic bistrimethylsilylmethyl anion quantitatively which reacted readily with aldehydes providing a general entry to vinylsilanes. The reaction of α-silylated ylides with non-enolizable aldehydes proceeded via selective Peterson-type elimination, in contrast to prior literature reports, providing a direct route to synthetically useful vinylphosphonium salts. The chemoselective formation of trialkylbenzyl phosphoranes in water and their Wittig reaction with aromatic and aliphatic aldehydes provided a practical, stereoselective and environmentally benign route to valuable trans-stilbenes and alkenes. The synthesis of the phytoalexin resveratrol was described. In addition, the method allowed for a gramscale synthesis of the anticancer agent DMU-212 utilizing no organic solvent at any stage. A direct synthesis of 1,3-dienes and 1,3,5-trienes from the reaction of semi-stabilized ylides and a range of saturated and unsaturated aldehydes was reported in water as solvent, employing sodium hydroxide as base. The water-soluble phosphine oxide side product was removed simply by aqueous partitioning of the organic products. | en_US |
dc.language.iso | en | en_US |
dc.subject | modified Peterson olefination | en_US |
dc.subject | new reactions | en_US |
dc.subject | carbanion chemistry | en_US |
dc.title | Recent Advances in Heteroatom-Stabilized Carbanion Chemistry | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | Chemistry | en_US |
dc.description.degreetype | Thesis | en_US |
dc.description.degree | Doctor of Philosophy (PhD) | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Das_Priyabrata_2009August_PhD.pdf | Thesis | 8.21 MB | Adobe PDF | View/Open |
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