An Aluminum Fluoride Complex with an Appended Ammonium Salt as an Exceptionally Active Cooperative Catalyst for the Asymmetric Carboxycyanation of Aldehydes.

Title An Aluminum Fluoride Complex with an Appended Ammonium Salt as an Exceptionally Active Cooperative Catalyst for the Asymmetric Carboxycyanation of Aldehydes.
Authors D. Brodbeck; F. Broghammer; J. Meisner; J. Klepp; D. Garnier; W. Frey; J. Kästner; R. Peters
Journal Angew Chem Int Ed Engl
DOI 10.1002/anie.201612493
Abstract

Al-F bonds are among the most stable ??bonds known, exhibiting an even higher bond energy than Si-F bonds. Despite a stability advantage and a potentially high Lewis acidity of Al-F complexes, they have not been described as structurally defined catalysts for enantioselective reactions. We show that Al-F salen complexes with appended ammonium moieties give exceptional catalytic activity in asymmetric carboxycyanations. In addition to aromatic aldehydes, enal and aliphatic substrates are well accepted. Turnover numbers up to around 10(4) were achieved, whereas with previous catalysts 10(1) -10(2) turnovers were typically attained. In contrast to Al-Me and Al-Cl salen complexes, the analogous Al-F species are remarkably stable towards air, water, and heat, and can be recovered unchanged after catalysis. They possess a considerably increased Lewis acidity as shown by DFT calculations.

Citation D. Brodbeck; F. Broghammer; J. Meisner; J. Klepp; D. Garnier; W. Frey; J. Kästner; R. Peters.An Aluminum Fluoride Complex with an Appended Ammonium Salt as an Exceptionally Active Cooperative Catalyst for the Asymmetric Carboxycyanation of Aldehydes.. Angew Chem Int Ed Engl. 2017. doi:10.1002/anie.201612493

Related Elements

Aluminum

See more Aluminum products. Aluminum (or Aluminium) (atomic symbol: Al, atomic number: 13) is a Block P, Group 13, Period 3 element with an atomic weight of 26.9815386. It is the third most abundant element in the earth's crust and the most abundant metallic element. Aluminum Bohr Model Aluminum's name is derived from alumina, the mineral from which Sir Humphrey Davy attempted to refine it from in 1812. Aluminum was first predicted by Antoine Lavoisier 1787 and first isolated by Hans Christian Øersted in 1825. Aluminum is a silvery gray metal that possesses many desirable characteristics. It is light, nonmagnetic and non-sparking. It stands second among metals in the scale of malleability, and sixth in ductility. It is extensively used in many industrial applications where a strong, light, easily constructed material is needed. Elemental AluminumAlthough it has only 60% of the electrical conductivity of copper, it is used in electrical transmission lines because of its light weight. Pure aluminum is soft and lacks strength, but alloyed with small amounts of copper, magnesium, silicon, manganese, or other elements, it imparts a variety of useful properties.

Fluorine

Fluorine is a Block P, Group 17, Period 2 element. Its electron configuration is [He]2s22p5. The fluorine atom has a covalent radius of 64 pm and its Van der Waals radius is 135 pm. In its elemental form, CAS 7782-41-4, fluorine gas has a pale yellow appearance. Fluorine was discovered by André-Marie Ampère in 1810. It was first isolated by Henri Moissan in 1886.

Nitrogen

See more Nitrogen products. Nitrogen is a Block P, Group 15, Period 2 element. Its electron configuration is [He]2s22p3. Nitrogen is an odorless, tasteless, colorless and mostly inert gas. It is the seventh most abundant element in the universe and it constitutes 78.09% (by volume) of Earth's atmosphere. Nitrogen was discovered by Daniel Rutherford in 1772.

Related Forms & Applications