Dimethyl itaconate → HCID 9964174, compound

HRID 546331Notes

Reaction equation

HRID 546331 reaction equation
[C:1]([O:10][CH3:11])(=[O:9])[C:2]([CH2:4][C:5]([O:7][CH3:8])=[O:6])=[CH2:3].C(O)[C@H](O)[C@H]1OC(=O)C(O)=C1O.[H][H]>C1([C@@H]2CC[C@@H](C3C=CC=CC=3)P2C2C(=O)OC(=O)C=2P2[C@H](C3C=CC=CC=3)CC[C@H]2C2C=CC=CC=2)C=CC=CC=1.F[B-](F)(F)F.[Rh+].C1CCC=CCCC=1.CO>[CH3:11][O:10][C:1](=[O:9])[C@@H:2]([CH3:3])[CH2:4][C:5]([O:7][CH3:8])=[O:6]

Participants

6

Reactant 3

HCID 69240Dimethyl itaconateHCID 54670067L-Ascorbic AcidHCID 178418361HCID 178418361, compound2×

Product 1

HCID 9964174HCID 9964174, compound

Reagents, catalysts & solvents 2

HCID 178420250HCID 178420250, compoundCatalystHCID 887MethanolSolvent

Conditions

Temperature
25 °C

Procedure

The reaction was carried out in an Argonaut Endeavor hydrogenation vessel. The glass liner was charged with dimethyl itaconate (316 mg, 2.0 mmol) and 3,4-bis[(S,S)-2,5-diphenyl-phospholan-1-yl]-furan-2,5-dione-(1,5-cyclooctadiene) rhodium(I) tetrafluoroborate (1.7 mg, 0.002 mmol, S/C 1000). The vessel was charged to 10 bar nitrogen and vented (×5). Degassed methanol (4 ml) was added. The vessel was charged to 10 bar nitrogen and vented (×2). Stirring was commenced at 1000 rpm and the contents were heated to 25° C. The vessel was charged to 10 bar hydrogen. Hydrogen uptake was complete after 16 h. The mixture was vented and evaporated to give (S)-2-methylsuccinic acid dimethyl ester, conversion 100%, ee 96.6% (Chiraldex GTA, 30 m×0.25 mm, injector/detector 180° C., helium 14 psi, 90° C. for 6 min then ramp at 1° C./min to 105° C., retention times S 10.11 minutes, R 10.48 minutes). In comparison, much lower enantioselectivity, of 60.2% ee, is reported by Holz, J. et al, ibid., for the same transformation, at S/C 100 in methanol, catalysed by the corresponding rhodium complex of Me-Malphos [i.e. the analogue of ligand (7) with Me groups at the 2- and 5-position of each phospholane ring]. Holz, J. et al also report that a change of solvent, to THF, increases the enantioselectivity to 86% ee but this still falls short of the 96.6% ee achieved in the current example at a higher S/C ratio.

Workup

  1. additionThe vessel was charged to 10 bar nitrogen
  2. additionThe vessel was charged to 10 bar nitrogen
  3. customevaporated

Sources & evidence

ORD record
ord-9565ea95400b460298ab8c4606eaa173
Source dataset
uspto-grants-2011_05
Patent number
US07935841B2

Reaction notes

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