Aldol addition reaction is one of the most important and most studied carbon-carbon bond
forming reactions in organic chemistry. Recent studies focused on the catalytic version of
this chemistry. Different from the classical Mukaiyama-type aldol reactions, chiral lewis
bases have been used as promoters. In the presence of SiCl4, these reactions proceed
through a cyclic transition state leading to anti aldol product as a major product with
moderate-to-good diastereo and enantioselectivities. Phosphoramide derivatives, BINAPO,
BINAPO derivatives, N,N-dioxides and N-oxides have been extensively used for this
purpose.
Recently, our group has designed new phosphine oxy aziridinyl phosphonates (POAP) as
chiral Lewis bases. These promoters were used for the asymmetric aldol addition reaction
between cyclohexanone and different aldehydes in the presence of SiCl4. Moreover, our
previously designed phosphine oxy ferrocenyl substituted aziridinyl methanol (POFAM)
ligands were also tested as Lewis bases. Among these 6 potential promoters, POAP-A gave
the best results, and the aldol product were obtained in moderate to good yields up to 80%,
and with moderate enantioselectivities (the highest, 66%) after standard optimization studies.
Aldehyde screening experiments provided the highest enantioselectivity (68%) with 2-
naphthaldehyde.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12615396/index.pdf |
| Date | 01 January 2013 |
| Creators | Tan, Duygu |
| Contributors | Dogan, Ozdemir |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | Access forbidden for 1 year |
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