Triisopropyl borate → (1S,2R)-4-[2-(tert-butyldimethylsilanyloxy)-1-methyl-4-pyridin-3-ylbutoxy]benzeneboronic acid
Reaction equation
C([Li])(C)(C)C.Br[C:7]1[CH:32]=[CH:31][C:10]([O:11][C@H:12]([C@H:14]([O:23][Si:24]([C:27]([CH3:30])([CH3:29])[CH3:28])([CH3:26])[CH3:25])[CH2:15][CH2:16][C:17]2[CH:18]=[N:19][CH:20]=[CH:21][CH:22]=2)[CH3:13])=[CH:9][CH:8]=1.C([O:36][B:37](OC(C)C)[O:38]C(C)C)(C)C>O1CCCC1>[Si:24]([O:23][C@H:14]([CH2:15][CH2:16][C:17]1[CH:18]=[N:19][CH:20]=[CH:21][CH:22]=1)[C@H:12]([CH3:13])[O:11][C:10]1[CH:31]=[CH:32][C:7]([B:37]([OH:38])[OH:36])=[CH:8][CH:9]=1)([C:27]([CH3:30])([CH3:29])[CH3:28])([CH3:26])[CH3:25]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- -78 °C
Procedure
A solution of tert-butyllithium (3.95 ml, 1.7M in hexanes) was added over a 1 hour period to a solution of (2S,3R)-2-(4-bromophenoxy)-3-tert-butyldimethylsilyloxy-5-pyridin-3-ylpentane (2.518 g, Example 15e)) and tri-isopropylborate (1.68 ml) in tetrahydrofuran (20 ml) at -78° C. The resulting solution was stirred at -78° C. for 2 hours and was then quenched by the addition of a saturated solution of ammonium chloride in water (50 ml). The mixture was poured into water (50 ml) and extracted into ethyl acetate (2×50 ml). The combined extracts were dried over anhydrous magnesium sulfate, filtered and evaporated. The residue was purified by chromatography on silica gel eluting with ethyl acetate and then ethyl acetate:methanol (4:1) to afford the sub-title compound as a foam (1.22 g).
Workup
- customwas then quenched by the addition of a saturated solution of ammonium chloride in water (50 ml)
- additionThe mixture was poured into water (50 ml)
- extractionextracted into ethyl acetate (2×50 ml)
- dry with materialThe combined extracts were dried over anhydrous magnesium sulfate
- filtrationfiltered
- customevaporated
- customThe residue was purified by chromatography on silica gel eluting with ethyl acetate
Sources & evidence
- ORD record
- ord-9ace0c48d3264676a5144925d8e9ea02
- Source dataset
- uspto-grants-2000_11
- Patent number
- US06143751
Reaction notes
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