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14 Cards in this Set
- Front
- Back
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What is the Negishi reaction? What can the RX group be? |
Organozinc cross coupling Pd (0) X - halide, OTf R - no B-hydrides |
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What makes a better Pd (0) precursor? Give examples. |
- e- rich ligands - bidentate ligands E.g. (Ph3P)4Pd (Ph3P)2Pd |
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What does the Stille reaction involve? What makes a good RX group? |
organostannes cross coupling of alkenes/aryl rings. Alkanes dont transmetallate well |
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How can you synthesise a diene? |
The Stille reaction: 1) attach alkyne to organostannane -> alkene-stannane 2) Wittig reduction of ketone to alkene 3) Stille reaction of 2 alkenes |
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What are the reagents for Suzuki coupling? |
Boronic acid/ester Base (eg. NaOtBu) |
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How can you use Suzuki coupling to make an alkene? |
Vinyl-boron Terminal alkyne + boronic ester |
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How can you use Suzuki coupling to make an alkyne? |
Terminal alkyne + RX -CuI catalyst -NEt3 |
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How can you make an R-amine bond? |
1) Ar-X + amine -> (Pd cat, base) -> Ar-amine 2) organostannane Ar-X +Bu3Sn-NH2 -> (Pd cat., NaOtBu) -> Ar-NH2 |
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What are the steps of the Heck reaction? |
1) Oxidative addition of RX to Pd(0) 2) Alkene association 3) Ligand combination - Pd adds to more substituted C 4) B-hydride transfer 5) Elimination |
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When does the Reductive Heck reaction happen? |
An alkene with no accessible B-hydrogens. -Instead, AcO- attaches to Pd to kick out LG -releases CO2 and leaves Pd-H -Red. elimination of Pd leaves alkane |
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What are the possible products of allylic alcohols? |
1) R-allylic alcohol with R attached to least substituted position 2) Enol -> Ketone by elimination of H next to -OH |
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Allylic substitution of -OAc does not occur normally. What is the mechanism with Pd(0) ? |
Alkene association to Pd, kicks out OAc Resonance structure associated with Pd Nuc. attack on least hindered C |
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What is TMM chemistry? Reagents, products |
TMM - trimethalenemethane Cyclisation reaction Pd association to allylic fragment attached to carbanion Carbanion attacks double bond Double bond molecule attacks back at Pd end Ring formed! Voila!!! |
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How do you make a desired boronic ester? |
React RX with BuLi -> R-Li R-Li + B(OMe)3 -> R-B(OMe)2 |
