(Triphenylphosphoranylidene)acetonitrile → ((R)-3-cyano-1-methyl-allyl)-carbamic acid tert-butyl ester

HRID 246215Notes

Reaction equation

HRID 246215 reaction equation
[C:1]([O:5][C:6](=[O:12])[NH:7][C@H:8]([CH3:11])[CH:9]=O)([CH3:4])([CH3:3])[CH3:2].C1(P(=[CH:32][C:33]#[N:34])(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>ClCCl>[C:1]([O:5][C:6](=[O:12])[NH:7][C@H:8]([CH3:11])[CH:9]=[CH:32][C:33]#[N:34])([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 85524(Triphenylphosphoranylidene)acetonitrileHCID 10910049tert-butyl N-((2R)-1-oxopropan-2-yl)carbamate

Product 1

HCID 86677956((R)-3-cyano-1-methyl-allyl)-carbamic acid tert-butyl esterYield 63.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

In a 20 mL scintillation vial, ((R)-1-methyl-2-oxo-ethyl)-carbamic acid tert-butyl ester (2.5 g, 14.4 mmol) and (triphenylphosphoranylidene)acetonitrile (6.52 g, 21.7 mmol) were mixed in dichloromethane (20 mL) and stirred at room temperature for 16 h. The solvent was evaporated to give the crude material, which was purified by column chromatography (silica gel, gradient n-hexanes ethyl acetate) to provide 1.8 g (63%) of ((R)-3-cyano-1-methyl-allyl)-carbamic acid tert-butyl ester in a 3:1 diastereoselectivity (E:Z) as a colorless oil. 1H NMR (300 MHz, CDCl3) δ ppm 6.38-6.79 (m, 1H), 5.47 (dd, J=16.24, 1.89 Hz, 1H), 4.48 (bs, 1H), 4.47 (bs, 1H), 1.45 (s, 1H), 1.28 (d, J=7.18 Hz, 9H).

Workup

  1. customThe solvent was evaporated
  2. customto give the crude material, which
  3. customwas purified by column chromatography (silica gel, gradient n-hexanes ethyl acetate)

Sources & evidence

ORD record
ord-fc346cea310b4a4e9983a907bd66bedf
Source dataset
uspto-grants-2014_02
Patent number
US08658646B2

Reaction notes

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