Dichotomy of Manganese Catalysis via Organometallic or Radical Mechanism: Stereodivergent Hydrosilylation of Alkynes

• Published in: Angewandte Chemie International Edition Vol. 57; no. 4; pp. 923 - 928
• Main Authors: Yang, Xiaoxu, Wang, Congyang
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 22.01.2018; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Alkynes; Arsenic; Catalysis; Chemistry; Chemistry, Multidisciplinary; homogeneous catalysis; Hydrosilylation; Manganese; Peroxide; Physical Sciences; Regioselectivity; Science & Technology; selectivity; Stereoselectivity; selectivity; alkynes; COMPLEXES; ALDEHYDES; manganese; C-H ACTIVATION; MARKOVNIKOV HYDROSILYLATION; homogeneous catalysis; hydrosilylation; CARBONYL; REGIO; HYDROSILATION; STEREOSELECTIVE HYDROSILYLATION; EFFICIENT; ALKENE HYDROSILYLATION
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201710206

Herein, we disclose the first manganese‐catalyzed hydrosilylation of alkynes featuring diverse selectivities. The highly selective formation of E‐products was achieved by using mononuclear MnBr(CO)5 with the arsenic ligand, AsPh3. Whereas using the dinuclear catalyst Mn2(CO)10 and LPO (dilauroyl peroxide) enabled the reversed generation of Z‐products in good to excellent stereo‐ and regioselectivity. Such a way of controlling the reaction stereoselectivity is unprecedented. Mechanistic experiments revealed the dichotomy of manganese catalysis via organometallic and radical pathways operating in the E‐ and Z‐selective routes, respectively. Dichotomy of Man(ganese): In the manganese‐catalyzed hydrosilylation of alkynes, a highly selective formation of E‐products was achieved by using mononuclear MnBr(CO)5 with AsPh3. However, with the dinuclear catalyst Mn2(CO)10 and LPO (dilauroyl peroxide) the Z‐products were obtained. Mechanistic experiments revealed catalysis via organometallic and radical pathways.