Cobalt- and iron-catalyzed regiodivergent alkene hydrosilylations

Abstract

A complementary set of base metal catalysts has been developed for regiodivergent alkene hydrosilylations: iron complexes of amine-iminopyridine ligands are selective for Markovnikov hydrosilylations (branched/linear up to >99:1), while the...

Research on inorganic activators of dibromo Co-terpyridine complex precatalyst for hydrosilylation

“…This result is in good agreement with the results described in previous reports on the activation of Fe and Co complexes by NaO t Bu. 23,24 Since first row transition metal complexes with carboxylato ligands such as [LM(OC(O)R) 2 ] have been reported to show catalytic activity for hydrosilylation without an activator, 13,16,19,27 we investigated the catalytic activity of [Co(tpy)Br 2 ] in the presence of potassium pivalate (KOPv) and found that KOPv effectively activated [Co(tpy)Br 2 ] (entries 5 and 6). It should be noted that a carboxylate anion can activate the Co complex, whether it is used as a ligand for the complex or added externally.…”

“…Relatively air-stable alkoxide salts such as NaO t Bu were reportedly good activators. [23][24][25] According to the proposed mechanism, an alkoxide nucleophilically attacks hydrosilane (HSiR 3 ) to form a silicate species [HSiR 3 (X)] − (Fig. 1), and the silicate exhibits reducing power (or hydride properties) to form an active species from the precatalyst [LMX 2 ].…”

Synthesis of aryl cobalt and iron complexes and their catalytic activity on hydrosilylation of alkenes

“…In recent years, there are more and more reports on alkene hydrosilylation catalyzed by base metals such as iron, [4][5][6][7][8][9] cobalt [9][10][11][12][13][14][15][16][17] and nickel. [18][19][20][21][22] However, in the construction of a ligand skeleton, most catalysts are metal complexes supported by bidentate ligands 6,16,20 or pincer ligands ([NNN], 7,18,19 [NNP] 4,5 [CNC] 11 and [PSiP] 13,14 ).…”

Photocatalytic Synthesis of Diarylmethyl Silanes via 1,6-Conjugate Addition of Silyl Radicals to p-Quinone Methides

“…Among them, the synthesis of benzylic silanes was a representative example. The most important synthetic method of benzylic silanes was transition-metal-catalyzed Markovnikov-type hydrosilylation of vinylarenes, including Co-, Fe-, Ni-catalyzed hydrosilylation of vinylarenes (Scheme , 2a) . In addition, transition metal catalyzed cross-coupling between α-heteroatom-substituted benzyl hydrocarbons and silicon nucleophiles can also be used for the preparation of benzylic silanes (Scheme , 2b) .…”