Aldehyde Reduction by a Pyridone Borane Complex through Boron‐Ligand‐Cooperation: Concerted or Not?. Issue 2 (23rd August 2018)

• Record Type: Journal Article
• Authors: Müller, Tizian; Hasenbeck, Max; Becker, Jonathan; Gellrich, Urs
• Other Names: Schreiner Peter R. guestEditor.
• Is Part Of: European journal of organic chemistry. Issue 2/3(2019)
• Page Start: 451
• Page End: 457
• Publication Date: 2018-08-23
• Subjects: Boron ligand cooperation -- Coupled cluster computations -- Frustrated Lewis pairs -- Aldehydes -- Reduction -- Hydrogenation; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201800847
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : The reduction of benzaldehyde by a pyridone borane complex was investigated by NMR, X‐ray analysis as well as DFT and DLPNO‐CCSD(T) computations. The reaction leads to the formation of a pyridone boronic ester complex stabilized by an NH··· O hydrogen bond. The computations show that the hydrogenation takes place in a concerted fashion, yielding a transient benzyl alcohol boroxypyridine complex that undergoes a barrierless O–H addition. The concerted hydrogen transfer is associated with a transformation of a pyridone borane to a boroxypyridine, and thus with the interconversion of a neutral donor ligand to a covalently bound substituent. Abstract : Aldehyde reduction by a pyridone borane complex was studied experimentally and computationally. The results indicate that a concerted hydrogen transfer mechanism is operative, resulting in the formation of a transient alcohol complex that undergoes a barrierless addition. The concerted hydrogen transfer is associated with a pyridone borane to boroxypyridine transformation.