Diastereoselective and Enantioselective Heck Alkenylation of Cyclopent-3-en-1-ylmethanol with Alkenyl Triflates and Evaluation of Noncovalent Effects

Author(s)

de Oliveira, Valdeir C. ; Angnes, Ricardo A. ; Batista Jr, Joao M. ; Correia, Carlos Roque D.

• Document type: Journal article
• Source: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY; v. N/A, p. 9-pg., 2023-08-04.

Abstract

This work describes an effective method to obtain chiral vinyl cyclopentenols with a high degree of enantioselectivity and diastereoselectivity through Heck desymmetrization of cyclopent-3-en-1-ylmethanol using vinyl triflates as coupling agents and chiral N,N ligands. This Heck vinylation protocol allowed the synthesis of several structurally complex cyclopentenols in isolated yields of up to 80 % in enantiomeric ratios of up to 97 : 3 and diastereoselectivities higher than 20 : 1 in most cases. Experiments using (E) or (Z) vinyl triflates, and desymmetrization of protected olefin 1-(cyclopent-3-en-1-ylmethoxy)-4-nitrobenzene (17) were instrumental in rationalizing the observed diastereoselectivities of Heck products involving the interaction of vinyl triflate carbonyl and the hydroxyl group moiety of the substrate with the cationic Pd(II) complex. The absolute configuration of the vinylated Heck products was determined by Vibrational Circular Dichroism (VCD) spectroscopy. (AU)

• FAPESP's process: 13/07600-3 - CIBFar - Center for Innovation in Biodiversity and Drug Discovery
• Grantee: Glaucius Oliva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/25770-6 - New frontiers in cross-coupling reactions promoted by palladium: combining enantioselective catalysis, C-H activations, new materials and in flux reactions aiming at high efficiency and sustainability in synthetic processes
• Grantee: Carlos Roque Duarte Correia
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/22319-5 - Vibrational circular dichroism spectral markers: facilitating absolute configuration assignment of natural products
• Grantee: João Marcos Batista Junior
• Support Opportunities: Regular Research Grants