Details

Autor(en) / Beteiligte

• Chahal, Mandeep K.
• Payne, Daniel T.
• Matsushita, Yoshitaka
• Labuta, Jan
• Ariga, Katsuhiko
• Hill, Jonathan P.

Titel

Molecular Engineering of β‐Substituted Oxoporphyrinogens for Hydrogen‐Bond Donor Catalysis

Ist Teil von

• European journal of organic chemistry, 2020-01, Vol.2020 (1), p.82-90

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A new class of bifunctional hydrogen‐bond donor organocatalyst using oxoporphyrinogens having increased intramolecular hydrogen‐bond donor distances is reported. Oxoporphyrinogens are highly non‐planar rigid macrocycles containing a multiple hydrogen bond‐forming binding site. In this work, we describe the first example of non‐planar OxPs as hydrogen‐bond donor catalysts prepared using a molecular engineering approach of the binding site for dual activation of substrates. The introduction of β‐substituents is key to the catalytic activity and the catalysts are able to catalyze 1,4‐conjugate additions and sulfa‐Michael additions, as well as, Henry and aza‐Henry reactions at low catalyst loadings (≤ 1 mol‐%) under mild conditions. Preliminary mechanistic studies have been carried out and a possible reaction mechanism has been proposed based on the bi‐functional activation of both substrates through hydrogen‐bonding interactions. Beta functionalization of oxoporphyrinogens as H‐bond donor catalysts with binding site designed for dual activation of substrates is reported. Introduction of the β‐substituents enables the catalysis of 1,4‐conjugate additions, sulfa‐Michael additions and Henry/aza‐Henry reactions at low catalyst loadings (≤ 1 mol‐%) under mild conditions.