Bromide ion → HCID 10881195, compound

HRID 636908Notes

Reaction equation

HRID 636908 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[CH:8][C:7](Br)=[CH:6][CH:5]=1)=[O:3].Br[C:12]1[CH:19]=[CH:18][C:15]([CH:16]=[O:17])=[CH:14][CH:13]=1.I[C:21]1C=CC(Br)=CC=1.BrC1C=CC=CC=1C.BrC1C=CC=CC=1.ClC[C:45]([C:47]1C=CC=C[CH:48]=1)=[O:46].[Br-].[Li+].CC(C1C=CC(Cl)=CC=1)=O.C(OCC(CC)CCCC)(=O)C=C.C([O-])(=O)C.[Na+].[Li].[Br-]>[Pd].CC(N(C)C)=O.P1C2C(=CC=CC=2)C[Pd]1>[C:2]([C:4]1[CH:9]=[CH:8][C:7](/[CH:48]=[CH:47]/[C:45]([O:17][CH2:16][CH:15]([CH2:14][CH3:13])[CH2:18][CH2:19][CH2:12][CH3:21])=[O:46])=[CH:6][CH:5]=1)(=[O:3])[CH3:1]

Participants

16

Reactant 12

HCID 259Bromide ionHCID 72362-BromotolueneHCID 7466p-BromoacetophenoneHCID 7467P-ChloroacetophenoneHCID 76362-Ethylhexyl acrylateHCID 7961BromobenzeneHCID 107572-ChloroacetophenoneHCID 115221-Bromo-4-iodobenzeneHCID 707414-BromobenzaldehydeHCID 82050Lithium BromideHCID 517045Sodium AcetateHCID 3028194Lithium

Product 1

HCID 10881195HCID 10881195, compoundYield 82%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalyst2×HCID 178419896HCID 178419896, compoundCatalyst2×HCID 31374DimethylacetamideSolvent

Procedure

DE-4421730 discloses the hitherto best process using palladaphosphaindanes, known as palladacycles, for the Heck reaction. It comprises the reaction of bromoaromatics and chloroaromatics with olefins. Activated bromoaromatics, for example 4-bromoacetophenone, 4-bromobenzaldehyde or 4-iodobromobenzene, are reacted in yields of up to 100% using amounts of from 0.002 to 0.01 mol % of palladium catalyst in the form of palladaphosphaindane. Less active bromoaromatics, for example bromotoluene or bromobenzene, are reacted in yields of up to 96% using amounts of 2 mol % of palladium as catalyst in the form of palladaphosphaindane. In the reaction of activated chloroaromatics, for example chloroacetophenone, it is necessary to add halide ions in the form of their salts, for example lithium bromide, in order to achieve high yields. Thus, the reaction of 100 mmol of 4-chloroacetophenone, 170 mmol of 2-ethylhexyl acrylate, 110 mmol of sodium acetate, 10 mmol of lithium, bromide in 100 ml of dimethylacetamide with 0.05 mmol of di-μ-acetato-bis(o-(di-o-tolylphosphino)benzyl)dipalladium(II) (corresponds to 0.1 mol % of palladium) as catalyst gives a yield of 82% of 2-ethylhexyl trans-4-acetylcinnamate after 18 hours at 130° C. Since, owing to the complexity of the reaction mixtures, simple catalyst recycling is not possible when using palladaphosphaindanes either, the catalyst costs generally stand in the way of industrial implementation in the case of the less active bromoaromatics and chloroaromatics. In addition, in the case of the chloroaromatics, the addition of halides or pseudo halides is ecologically disadvantageous, especially since these do not contribute to the reaction but only serve to stabilize the palladaphosphaindanes.

Workup

  1. customin yields of up to 100%
  2. customin yields of up to 96%
  3. customIn the reaction of activated chloroaromatics

Sources & evidence

ORD record
ord-4088ac00b4db4df2a4076d308b52185d
Source dataset
uspto-grants-2001_02
Patent number
US06194627B1

Reaction notes

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