Reaction of lithium diphenylphosphonium di(methylide) with carbonic acid derivatives. A novel access to polyfunctional unsaturated esters and amides
Abstract The lithium diphenylphosphonium di(methylide) Ph 2 P(CH 2 ) 2 Li 1 readily attacks cyclic carbonates, carbamates, and thiocarbamates, resulting in “pseudo‐acylation” products, after a ring‐opening step. Thus, new stabilized ylides are prepared, which can be used in situ as carbonyl olefinat...
| Published in: | Heteroatom Chemistry |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1992
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1002/hc.520030416 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhc.520030416 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hc.520030416 |
| Summary: | Abstract The lithium diphenylphosphonium di(methylide) Ph 2 P(CH 2 ) 2 Li 1 readily attacks cyclic carbonates, carbamates, and thiocarbamates, resulting in “pseudo‐acylation” products, after a ring‐opening step. Thus, new stabilized ylides are prepared, which can be used in situ as carbonyl olefination reagents towards aldehydes. This procedure is a new one‐pot method for the synthesis of (E)‐vinylic esters and amides, bearing a free ω‐hydroxyl group. When a thiocarbamate is the initial substrate for 1 , a Michael‐type cyclization occurs, following the Wittig olefination, resulting in the one‐pot preparation of 7‐membered heterocycles. |
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