Phenylboronic Acid → Methyl 4-(biphenyl-3-ylmethyl)-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate

Participants

Reaction Steps

The title compound was synthesized in four steps. First tosyl protected methyl 4-oxo-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate (methyl 4-oxo-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate) (1.50 g, 8.37 mmol) was reacted with 3-bromobenzylmagnesium bromide (15 mL, 3.75 mmol) according to General Procedure 3 to give exo olefin-containing compound (E)-methyl 4-(3-bromobenzylidene)-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate, followed by coupling with phenylboronic acid (0.305 g, 2.50 mmol) according to General Procedure 9.2 to give (E)-methyl 4-(biphenyl-3-ylmethylene)-1-tosyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate, then tosyl deprotection according to General Procedure 10.1 to give (E)-methyl 4-(biphenyl-3-ylmethylene)-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate. Hydrogenation of (E)-methyl 4-(biphenyl-3-ylmethylene)-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate according to General Procedure 6 (with 5% Pd/C), then purification by column chromatography (Isco CombiFlash) eluting with a gradient of 0-20% EtOAc/heptane afforded the title compound: 0.041 g. 1H NMR (400 MHz, ACETONE-d6) δ ppm 2.09-2.19 (m, 1H) 2.50-2.60 (m, 1H) 2.60-2.68 (m, 2H) 2.86 (d, J=1.85 Hz, 1H) 2.88 (s, 1H) 3.31-3.39 (m, 1H) 3.71-3.72 (m, 3H) 6.36 (d, J=1.90 Hz, 1H) 7.21-7.25 (m, 1H) 7.26-7.30 (m, 1H) 7.31-7.51 (m, 5H) 7.61-7.67 (m, 2H) 10.49 (br.s, 1H).

Provenance & Evidence