(3E)-2-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-buten-2-ol

General procedure: Tri(2-furyl)phosphine (0.02 mmol, 4.7 mg) and [Rh(CO)2Cl]2 (0.01 mmol, 3.9 mg) were mixed in toluene (10 mL) at room temperature. After stirring for 10minutes, the alkyne (1 mmol) in toluene (1 mL) and 4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolane (1.2 mmol, 174 μL) were added into the mixture. The reaction was stirredunder N2 at room temperature and monitored by TLC. After quenching with H2O, thereaction mixture was extracted with Et2O. The organic phase was dried over MgSO4 andthen was concentrated under reduced vacuum. The residue was purified with columnchromatography on silica gel.General procedure: Dimethoxyethane (10 mL) and water (1 mL) were added to a mixture of ethyl 2- bromooxazole-5-carboxylate (Ark Pharm, 334 mg, 1.52 mmol), 3, 6-dihydro-2H-pyran-4- boronic acid pinacol ester (Combi-Blocks, 319 mg, 1.52 mmol) , [1, 1'- bis(diphenylphosphino)ferrocene]dichloropalladium(II) (89 mg, 0.12 mmol) and potassium carbonate (525 mg, 3.80 mmol) in a microwave tube. The tube was sealed and degassed three times with a nitrogen back flush each time. The tube was heated in a Biotage Initiator+ microwave reactor and irradiated at 115 C for 35 minutes. The seal was opened, and the reaction mixture was combined with silica gel (15 g) and concentrated under reduced pressure to a free flowing powder. The powder was directly purified via flash chromatography (SiO2, 15-100% ethyl acetate in heptane) to give the title compound (0.24 g, 1.08 mmol, 71% yield). The reaction and purification conditions described in Example 39A substituting (E)-2- methyl-4-(4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl)but-3-en-2-ol (Ark Pharm) for 3, 6- dihydro-2H-pyran-4-boronic acid pinacol ester, tris(dibenzylideneacetone)dipalladium(0) (Aldrich, 0.1 eq) and 1, 3, 5, 7-tetramethyl-6-phenyl-2, 4, 8-trioxa-6-phosphaadamantane (Aldrich, 0.2 eq) for [1, 1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and methyl 4- bromopicolinate (Combi-Blocks) for ethyl 2-bromooxazole-5-carboxylate gave the title compound. MS (ESI+) m/z 222 (M+H)+.General procedure: Dimethoxyethane (10 mL) and water (1 mL) were added to a mixture of ethyl 2- bromooxazole-5-carboxylate (Ark Pharm, 334 mg, 1.52 mmol), 3, 6-dihydro-2H-pyran-4-boronic acid pinacol ester (Combi-B locks, 319 mg, 1.52 mmol) , [Iota, Gamma- bis(diphenylphosphino)ferrocene]dichloropalladium(II) (89 mg, 0.12 mmol) and potassium carbonate (525 mg, 3.80 mmol) in a microwave tube. The tube was sealed and degassed three times with a nitrogen back flush each time. The tube was heated in a Biotage Initiator+ microwave reactor and irradiated at 115 C for 35 minutes. The seal was opened, and the reaction mixture was combined with silica gel (15 g) and concentrated under reduced pressure to a free flowing powder. The powder was directly purified via flash chromatography (Si(, 15- 100% ethyl acetate in heptane) to give the title compound (0.24 g, 1.08 mmol, 71 % yield). MS (ESI+) m/z 224 (M+H)+. The reaction and purification conditions described in Example 39A substituting (E)-2- methyl-4-(4, 4, 5, 5-tetramethyl-l , 3, 2-dioxaborolan-2-yl)but-3-en-2-ol (Ark Pharm) for 3, 6- dihydro-2H-pyran-4-boronic acid pinacol ester, tris(dibenzylideneacetone)dipalladium(0) (Aldrich, 0.1 eq) and l , 3, 5, 7-tetramethyl-6-phenyl-2, 4, 8-trioxa-6-phosphaadamantane (Aldrich, 0.2 eq) for [l , l'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), and methyl 4- bromopicolinate (Combi-B locks) for ethyl 2-bromooxazole-5-carboxylate gave the title compound. MS (ESI+) m/z 222 (M+H)+.General procedure: Tri(2-furyl)phosphine (0.02 mmol, 4.7 mg) and [Rh(CO)2Cl]2 (0.01 mmol, 3.9 mg) were mixed in toluene (10 mL) at room temperature. After stirring for 10minutes, the alkyne (1 mmol) in toluene (1 mL) and 4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolane (1.2 mmol, 174 muL) were added into the mixture. The reaction was stirredunder N2 at room temperature and monitored by TLC. After quenching with H2O, thereaction mixture was extracted with Et2O. The organic phase was dried over MgSO4 andthen was concentrated under reduced vacuum. The residue was purified with columnchromatography on silica gel.

Molecular Weight:212.10
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:2
Exact Mass:212.1583747
Monoisotopic Mass:212.1583747
Topological Polar Surface Area:38.7
Heavy Atom Count:15
Complexity:253
Defined Bond Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes