Reaction #47142

Reaction equation

triflate

1,1′-[[(Propane-1,3-diyl)dioxy]bis[(11S,11aS)-10-(2,2,2-trichloroethoxycarbonyl)-11-(tert-butyldimethylsilyloxy)-7-methoxy-2-[[(trifluoromethyl)sulfonyl]oxy]-1,10,11,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepin-5-one]]

LiCl

tributyl(phenylethynyl)tin

→

17

Yield 92.7%

1,1′-[[(Propane-1,3-diyl)dioxy]bis[(11S,11aS)-10-(2,2,2-trichloroethoxycarbonyl)-11-(tert-butyldimethylsilyloxy)-7-methoxy-2-ethynylphenyl-1,10,11,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepin-5-one]]

Yield 92.7%

Solvents

THF

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was heated
2. 2
   Temperatureat reflux for 2.5 h when TLC
3. 3
   Otherthe complete consumption of the starting material
4. 4
   Otherexcess solvent was removed
5. 5
   workup.DISSOLUTIONthe residue was dissolved in DCM (20 mL)
6. 6
   Washby washing with 10% NH4OH (20 mL)
7. 7
   ExtractionThe aqueous layer was extracted with DCM (3×20 mL)
8. 8
   Washwashed with brine (50 mL)
9. 9
   Dryingdried (MgSO4)
10. 10
    FiltrationFiltration and evaporation of solvent
11. 11
    Otherafforded the crude product which
12. 12
    Otherwas purified by flash column chromatography (80:20 v/v hexane/EtOAc)

Procedure

A catalytic amount of Pd(PPh3)4 was added to a stirred mixture of triflate 13 (193 mg, 0.13 mmol), LiCl (34 mg, 0.80 mmol, 6.0 eq) and tributyl(phenylethynyl)tin (0.14 mL, 157 mg, 0.40 mmol, 3.0 eq) in dry THF (5 mL). The reaction mixture was heated at reflux for 2.5 h when TLC showed the complete consumption of the starting material. After cooling to room temperature, excess solvent was removed and the residue was dissolved in DCM (20 mL), followed by washing with 10% NH4OH (20 mL). The aqueous layer was extracted with DCM (3×20 mL), and the organic extracts were combined, washed with brine (50 mL) and dried (MgSO4). Filtration and evaporation of solvent afforded the crude product which was purified by flash column chromatography (80:20 v/v hexane/EtOAc) to afford 17 as a yellow glass (162 mg, 90%): 1H NMR (400 MHz, CDCl3) δ 7.40-7.37 (m, 4H, H15), 7.26-7.19 (m, 10H, H3, H6, H16 and H17), 6.70 (s, 2H, H9), 5.85 (d, 2H, J=8.8 Hz, H11), 5.15 (d, 2H, J=12.0 Hz, Troc CH2), 4.24-4.19 (m, 2H, OCH2CH2CH2O), 4.12-4.02 (m, 4H, Troc CH2 and OCH2CH2CH2O), 3.86-3.79 (m, 8H, OCH3×2 and H11a), 3.15 (dd, 2H, J=10.8, 16.5 Hz, H1), 2.63 (d, 2H, J=16.5 Hz, H1), 2.37-2.35 (m, 2H, OCH2CH2CH2O), 0.82 (s, 18H, TBS CH3×6), 0.22 and 0.18 (s×2, 12H, TBS CH3×4); 13C NMR (100.6 MHz, CDCl3) δ 163.8 (Cquat), 153.6 (Cquat), 150.8 (Cquat), 149.3 (Cquat), 133.3 (C3), 131.4 (C15), 128.4 (C16 and C17), 127.8 (Cquat), 125.1 (Cquat), 123.0 (Cquat), 114.0 (C6), 110.0 (C9), 104.8 (Cquat), 95.2 (Troc CCl3), 93.7 (Calkyne), 86.9 (C11), 83.6 (Calkyne), 74.8 (Troc CH2), 66.0 (OCH2CH2CH2O), 61.4 (C11a), 56.2 (OCH3), 37.8 (C1), 28.8 (OCH2CH2CH2O), 25.6 (TBS CH3), 17.8 (TBS Cquat); MS (ES), m/z (relative intensity) 1344 (M+., 8), 625 (100).

Source