Regioselective Formation of (E)‐β‐Vinylstannanes with a Topologically Controlled Molybdenum‐Based Alkyne Hydrostannation Catalyst. Issue 23 (3rd May 2018)

• Record Type: Journal Article
• Authors: Mandla, Kyle A.; Moore, Curtis E.; Rheingold, Arnold L.; Figueroa, Joshua S.
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 23(2018)
• Page Start: 6853
• Page End: 6857
• Publication Date: 2018-05-03
• Subjects: alkynes -- catalysis -- hydrostannation -- isocyanides -- molybdenum; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201802397
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The regioselective formation of ( E )‐β‐vinylstannanes has been a long‐standing challenge in transition‐metal‐catalyzed alkyne hydrostannation. Herein, we report a well‐defined molybdenum‐based system featuring two encumbering m ‐terphenyl isocyanides that reliably and efficiently delivers ( E )‐β‐vinylstannanes from a range of terminal and internal alkynes with high regioselectivity. The system is particularly effective for aryl alkynes and can discriminate between alkyl chains of low steric hindrance in unsymmetrically substituted dialkyl alkynes. Catalytic hydrostannation with this system is also characterized by an electronic effect that leads to a decrease in regioselectivity when electron‐withdrawing groups are present on the alkyne substrate. Abstract : Opposite sides : Alkyne hydrostannation catalysts are traditionally effective at providing 1, 1‐vinylstannanes (α‐products), with the selective delivery of E ‐configured 1, 2‐vinylstannanes (( E )‐β‐products) being much more challenging. Reported here is a molybdenum/isocyanide‐based catalyst that overcomes this difficulty with high regioselectivity.