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. Author manuscript; available in PMC: 2019 Feb 12.
Published in final edited form as: J Am Chem Soc. 2017 Sep 20;139(39):13882–13896. doi: 10.1021/jacs.7b07706

Scheme 4. Synthesis of Vinyl Arene Intermediate 31 for Photocycloadditiona.

Scheme 4

aReaction conditions: (a) H2, Pd/C (cat.), EtOAc, 23 °C; (b) LiHMDS, then PhNTf2, THF, –78 to 23 °C, 88% over two steps; (c) NaCN, CuI (cat.), Pd(PPh3)4 (cat.), MeCN, 78%; (d) aryl boronic ester (prepared from the corresponding ArBr, n-BuLi, Et2O, –78 to 23 °C; then B(OMe)3, –40 °C); then 12, [Rh(cod)OH]2 (cat.), H2O, 1,4-dioxane, 100 °C, 69%; (e) Red-Al, CH2Cl2, 0–23 °C, 77%; (f) DMP, NaHCO3, CH2Cl2, 89%; (g) PPh3MeBr, LiHMDS, THF, 70 °C; then 26, 0–23 °C, 98%; (h) 28, [Rh(PPh3)3Cl] (cat.), PhMe, 130 °C, 65–75%; (i) PhI(OAc)2, KOH, MeOH, 94%; (j) TBAF, THF, 23 °C, 94% over two steps; (k) MsCl, CH2Cl2; (l) KH, DMF, 60 °C, 86% over two steps. TBAF = tetrabutylammonium fluoride. DMP = Dess Martin periodinane.