4,4,5,5-Tetramethyl[1,3,2]dioxaborolane → (3R,4S)-tert-butyl 3-acetamido-3-(tert-butylcarbamoyl)-4-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)pyrrolidine-1-carboxylate

HRID 590699

Reaction equation

HRID 590699 reaction equation
[C:1]([NH:4][C@:5]1([C:20](=[O:26])[NH:21][C:22]([CH3:25])([CH3:24])[CH3:23])[C@@H:9]([CH2:10][CH:11]=[CH2:12])[CH2:8][N:7]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:6]1)(=[O:3])[CH3:2].[CH3:27][C:28]1([CH3:35])[C:32]([CH3:34])([CH3:33])[O:31][BH:30][O:29]1>C(Cl)Cl.[Ir].ClC1CCC=CCCC=1.C1(P(C2C=CC=CC=2)CCP(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[C:1]([NH:4][C@:5]1([C:20](=[O:26])[NH:21][C:22]([CH3:25])([CH3:24])[CH3:23])[C@@H:9]([CH2:10][CH2:11][CH2:12][B:30]2[O:31][C:32]([CH3:34])([CH3:33])[C:28]([CH3:35])([CH3:27])[O:29]2)[CH2:8][N:7]([C:13]([O:15][C:16]([CH3:17])([CH3:18])[CH3:19])=[O:14])[CH2:6]1)(=[O:3])[CH3:2]

Participants

6

Reactant 2

HCID 27347684,4,5,5-Tetramethyl[1,3,2]dioxaborolaneHCID 69669632rel-(3R,4S)-tert-Butyl 3-acetamido-4-allyl-3-(tert-butylcarbamoyl)pyrrolidine-1-carboxylate

Product 1

HCID 67517991(3R,4S)-tert-butyl 3-acetamido-3-(tert-butylcarbamoyl)-4-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)pyrrolidine-1-carboxylateYield 82.5%

Reagents, catalysts & solvents 3

HCID 742671,2-Bis(diphenylphosphino)ethaneCatalystHCID 86594784Chloro-1,5-cyclooctadiene iridiumCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
-20 °C

Procedure

A stirred solution of (3R,4S)-tert-butyl 3-acetamido-4-allyl-3-(tert-butylcarbamoyl)pyrrolidine-1-carboxylate (5.51 g, 15 mmol) in anhydrous methylene chloride (80 mL) under nitrogen was treated with chloro-1,5-cyclooctadiene iridium dimer (0.252 g, 0.375 mmol) and 1,2-bis(diphenylphosphino)ethane (0.299 g, 0.75 mmol), stirred for 30 min, and cooled (−20° C.). 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (3.30 mL, 22.5 mmol) was added dropwise, and the solution was placed in an ice bath and allowed to reach room temperature overnight (18 h). The mixture was quenched with water (75 mL), stirred 15 min, and extracted with ethyl acetate (400 mL, then 2×100 mL). The combined organic solution was washed with saturated aqueous sodium chloride (150 mL), dried (MgSO4), and concentrated. The solid was recrystallized (2 crops) from acetonitrile to afford (3R,4S)-tert-butyl 3-acetamido-3-(tert-butylcarbamoyl)-4-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)propyl)pyrrolidine-1-carboxylate (6.13 g, 82%) as a white solid. NMR (CDCl3) δ 6.40-6.60 (m, 1 H), 6.23 (s, 1 H), 3.95-4.05 (m, 1 H), 3.65-3.75 (m, 2 H), 2.90-3.20 (m, 2 H), 2.00 (s, 3 H), 1.45 (s, 9 H), 1.30-1.45 (m, 4 H), 1.33 (s, 9 H), 1.22 (s, 12 H), 0.70-0.80 (m, 2 H). MS (m+1): 496.4.

Workup

  1. customthe solution was placed in an ice bath
  2. waitto reach room temperature overnight
  3. custom(18 h)
  4. customThe mixture was quenched with water (75 mL)
  5. stirringstirred 15 min
  6. extractionextracted with ethyl acetate (400 mL
  7. washThe combined organic solution was washed with saturated aqueous sodium chloride (150 mL)
  8. dry with materialdried (MgSO4)
  9. concentrationconcentrated
  10. customThe solid was recrystallized (2 crops) from acetonitrile

Sources & evidence

ORD record
ord-c0529111b9e0413fba81ba534427e210
Source dataset
uspto-grants-2016_01
Patent number
US09233985B2

Linked notes

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