Frustrated Lewis pair catalyzed hydrosilylation and hydrosilane mediated hydrogenation of fulvenes

Abstract

The frustrated Lewis pair (FLP) mediated hydrosilylation of pentafulvenes is described yielding allyl silanes with high regioselectivity in excellent yields. While phenyl substituted allyl silanes undergo B(C6F5)3-mediated rearrangement to vinyl silanes, dimethyl derivatives experience FLP-catalyzed hydrogenation followed by an unprecedented protodesilylation. This observation allowed the metal-free hydrogenation of 6,6-dimethylfulvene to iso-propyl cyclopentene according to a FLP-catalyzed triple domino reaction consisting of hydrosilylation, hydrogenation and protodesilylation. The mechanisms were investigated by deuteration experiments.

Preparation of a Key Tetraene Precursor for the Synthesis of Long Acenes

“…was obtained as a yellow oil and used in next step without any further purification. 1 H NMR and 13 C NMR were in agreement with the published data for 2 prepared at the 5 mmol scale , …”

“…1 H NMR and 13 C NMR were in agreement with the published data for 2 prepared at the 5 mmol scale. [36,37] (1S,2R,6S,7R) (3a) and (1S,2S,6R,7R)-10-Isopropylidene-4-oxatricyclo[5.2.1.02.6]dec-8-ene-3,5-dione (3b): 5-(Propan-2-ylidene)cyclopenta-1,3-diene 2 (139 g, 1.31 mol) was dissolved in dichloromethane (600 mL) under argon and then maleic anhydride (135 g, 1.38 mol, 1.05 equiv.) was added as a solid.…”

Radical‐Initiated Dismutation of Hydrosiloxanes by Catalytic Potassium‐Graphite

“…Hydrosilanes are convenient reagents in reduction reactions thanks to their polarized Si−H bond, which make them good hydride donors . They can be used in multiple reduction reactions using organometallic complexes or organic catalysts of inorganic salts . Among the most reactive hydrosilanes, silane (or monosilane), SiH 4 , can be obtained from the disproportionation of triethoxysilane (TES).…”

“…[1] They can be used in multiple reduction reactions using organometallic complexes or organic catalysts of inorganic salts. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Among the most reactive hydrosilanes, silane (or monosilane), SiH 4 , can be obtained from the disproportionation of triethoxysilane (TES). Silane has been used as precursor for the production of high purity silicon applications, [18][19][20] and for the hydrosilylation of olefins.…”

Lewis Acid Promoted Regioselective Double Hydro(hetero)arylation of 6,6′‐Dialkyl‐Substituted Pentafulvenes: A Facile Approach to Bisindole Derivatives

“…[5] Soon after, Paradies and coworkers effectively utilized a catalytic FLP for the hydrosilylation and subsequent hydrogenation of pentafulvenes to form silylated cyclopentenes. [6] As part of our continuing interest in the endocyclic activation of pentafulvene, [7,8] we have also developed catalytic protocols for the generation of C-3cyclopentannulated indoles and bisindoles by the application of transition-metal catalysts and Lewis acids. [1,9] In recent years, much attention has been devoted to the development of transi- tion, we have also demonstrated a hydro(hetero)arylation-dehydroxylation reaction of 2-hydroxy-substituted pentafulvenes to afford bisindole derivatives with isoprenyl-substituted cyclopentene moieties.…”