Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

• Published in: Tetrahedron letters Vol. 55; no. 2; pp. 346 - 350
• Main Authors: Faraji, Laleh, Jadidi, Khosrow, Notash, Behrouz
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 08.01.2014; Elsevier
• Subjects: Amino acids; Asymmetric addition; Asymmetry; Benzaldehyde; Carbenes; Chemistry; Chemistry, Organic; Chiral N-heterocyclic carbene; Couplings; Hydroxyalkyl-imidazolium salt; Ligands; Magnesium oxide; MgO nanoparticles; Mizoroki–Heck reaction; Nanoparticles; Physical Sciences; Science & Technology; BANGDLLVZXQURX-MNMPKAIFSA-M; BSCQKFSSHOJKKC-GOTSBHOMSA-N; CEBMFCQUIZFUCI-SFTDATJTSA-N; PFBQVGXIMLXCQB-VMPITWQZSA-N; YTLLYONRZLAGGG-GWDXTYQXSA-L; Hydroxyalkyl-imidazolium salt; FEJFVSMKLLOHAX-GRTNUQQKSA-M; USBFPTZNNAOAEA-IODNYQNNSA-M; FVVNCRMEGJFCPL-CMDGGOBGSA-N; LCYBPWGRHMFWLS-IAGOWNOFSA-N; HJXHHJSWXWBBKE-RBUKOAKNSA-N; MgO nanoparticles; QLFLAEUKYOZIRX-IODNYQNNSA-N; BAFWQPJAQWSLFW-YADHBBJMSA-N; BHUARXIVVXDKFK-PMACEKPBSA-N; QZMHRVZBTSJSQP-JKSUJKDBSA-N; YJYAVTQHXUJUOW-GRTNUQQKSA-M; PULXRDQEVGFVQP-JAXOOIEVSA-M; LANIZVZDSBVPBY-IRXDYDNUSA-N; DYUQAZSOFZSPHD-VIFPVBQESA-N; ZWKNLRXFUTWSOY-QPJJXVBHSA-N; Mizoroki–Heck reaction; QADAEJHCERWKBH-MOPGFXCFSA-N; KBIGLGQUSQTQFT-ZEQRLZLVSA-N; ZKTPOJYXSAETED-FKLPMGAJSA-M; CPJVCYXYMUJVJV-UMIAIAFLSA-M; LWMYHZDODWVPRN-FKLPMGAJSA-M; TXCCOHPEEJZMPS-PMACEKPBSA-N; PZWQAYHCYMVTFL-CVEARBPZSA-N; Chiral N-heterocyclic carbene; CHRNPMRUNQQELH-SJEIDVEUSA-M; KKYVXWZBOILKFQ-CTHHTMFSSA-M; ZIVKIYOCUVVPKF-IDVLALEDSA-M; KBEBGUQPQBELIU-CMDGGOBGSA-N; CCRCUPLGCSFEDV-BQYQJAHWSA-N; DWOFFEPFXQVXEL-JAXOOIEVSA-N; QDARLNPZKTVADU-ROUUACIJSA-N; PJANXHGTPQOBST-VAWYXSNFSA-N; Asymmetric addition; NEHJTMVJLKIGSV-QJHJCNPRSA-M; IMKVSWPEZCELRM-CMDGGOBGSA-N; ENANTIOSELECTIVE SYNTHESIS; COMPLEXES; ALDEHYDES; VINYLALUMINUM REAGENTS; Mizoroki-Heck reaction; REDUCTION; AMINO-ACIDS; NHC LIGANDS; CHEMISTRY; PRECATALYST; METATHESIS
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2013.11.027

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.