1-methoxy-1-oxo-1lambda5-phosphinan-4-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl 3-amino-5-(3,3-dimethylbut-1-ynyl)thiophene-2-carboxylate (474 mg, 2 mmol) and 1-Methoxy-1-oxo-1λ5 phosphinan-4-one (390 mg, 2.4 mmol) in THF (1 mL) and DMF (1 mL) was treated with dibutyltin dichloride (60 mg, 0.2 mmol). After 5 min, phenylsilane (272 μL, 2.2 mmol) was added, and the mixture was stirred for one hour at room temperature and then partitioned between water and ethyl acetate. The aqueous phase was extracted with ethyl acetate. The combined organic layers were washed with 5% LiCl and brine, dried over magnesium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography using EtOAc:Hexanes as eluent to provide 650 mg (85%) of title compound: MS (m/z) 384.0 [M+H]−; HPLC retention time: 4.463 min (2-98% acetonitrile:water with 0.05% trifluoroacetic acid). partitioned between water and ethyl acetate The aqueous phase was extracted with ethyl acetate The combined organic layers were washed with 5% LiCl and brine dried over magnesium sulfate filtered concentrated The residue was purified by silica gel column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-(N-(4-aminocyclohexyl)-4-methylcyclohexanecarboxamido)-5-(3,3-dimethylbut-1-ynyl)thiophene-2-carboxylic acid hydrochloride (40 mg, 0.083 mmol) and 1-methoxy-1-oxo-1λ5-phosphinan-4-one (27 mg, 0.166 mmol) were dissolved in 2 mL of DMF. Sodium triacetoxyborohydride (35 mg, 0.166 mmol) was added. The reaction mixture was allowed to stir at room temperature over 18 hours, and then diluted with EtOAc, washed with saturated sodium bicarbonate and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated. The residue was purified by HPLC (Gemini column; 5% acetonitrile:water, 5 min; 5-100% acetonitrile:water, 18 min; 100% acetonitrile, 6 min; both solvents containing 0.1% trifluoroacetic acid) to give title compound (38.6 mg): MS (m/z): 591.3 [M+H]−; HPLC retention time: 3.28 min (2-98% acetonitrile:water with 0.05% trifluoroacetic acid). washed with saturated sodium bicarbonate and brine The organic layer was dried over magnesium sulfate filtered concentrated The residue was purified by HPLC (Gemini column water, 5 min water, 18 min 100% acetonitrile, 6 min both solvents containing 0.1% trifluoroacetic acid)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of methyl 3-amino-5-(3,3-dimethylbut-1-ynyl)thiophene-2-carboxylate (474 mg, 2 mmol) and 1-Methoxy-1-oxo-1λ5 phosphinan-4-one (390 mg, 2.4 mmol) in THF (1 mL) and DMF (1 mL) was treated with dibutyltin dichloride (60 mg, 0.2 mmol). After 5 min, phenylsilane (272 μL, 2.2 mmol) was added, and the mixture was stirred for one hour at room temperature and then partitioned between water and ethyl acetate. The aqueous phase was extracted with ethyl acetate. The combined organic layers were washed with 5% LiCl and brine, dried over magnesium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography using EtOAc:Hexanes as eluent to provide 650 mg (85%) of title compound: MS (m/z) 384.0 [M+H]+; HPLC retention time: 4.463 min (2-98% acetonitrile:water with 0.05% trifluoroacetic acid). partitioned between water and ethyl acetate The aqueous phase was extracted with ethyl acetate The combined organic layers were washed with 5% LiCl and brine dried over magnesium sulfate filtered concentrated The residue was purified by silica gel column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-(N-(4-aminocyclohexyl)-4-methylcyclohexanecarboxamido)-5-(3,3-dimethylbut-1-ynyl)thiophene-2-carboxylic acid hydrochloride (40 mg, 0.083 mmol) and 1-methoxy-1-oxo-1λ5-phosphinan-4-one (27 mg, 0.166 mmol) were dissolved in 2 mL of DMF. Sodium triacetoxyborohydride (35 mg, 0.166 mmol) was added. The reaction mixture was allowed to stir at room temperature over 18 hours, and then diluted with EtOAc, washed with saturated sodium bicarbonate and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated. The residue was purified by HPLC (Gemini column; 5% acetonitrile:water, 5 min; 5-100% acetonitrile:water, 18 min; 100% acetonitrile, 6 min; both solvents containing 0.1% trifluoroacetic acid) to give title compound (38.6 mg): MS (m/z): 591.3 [M+H]−; HPLC retention time: 3.28 min (2-98% acetonitrile:water with 0.05% trifluoroacetic acid). washed with saturated sodium bicarbonate and brine The organic layer was dried over magnesium sulfate filtered concentrated The residue was purified by HPLC (Gemini column water, 5 min water, 18 min 100% acetonitrile, 6 min both solvents containing 0.1% trifluoroacetic acid)

Conditions: temp:0.00; pressure:0.00; stir: