Practical Method for the Catalytic Enantioselective Arylation and Heteroarylation of Ketones with Organotitanium Reagents Generated in situ from Bromide and Heteroarene Precursors.

Title Practical Method for the Catalytic Enantioselective Arylation and Heteroarylation of Ketones with Organotitanium Reagents Generated in situ from Bromide and Heteroarene Precursors.
Authors A. Matsuda; T. Ushimaru; Y. Kobayashi; T. Harada
Journal Chemistry
DOI 10.1002/chem.201701395
Abstract

A practically useful, catalytic enantioselective method has been developed for the synthesis of tertiary diaryl and aryl heteroaryl carbinols starting from commercially available aromatic ketones and aryl or heteroaryl bromides. In this method, organotitanium reagents are generated in situ from the bromides by lithiation with BuLi followed by transmetallation of the resulting organolithiums with ClTi(OiPr)3. Treatment of the ketones with the titanium reagents in the presence of (R)-3-(3,5-bistrifluoromehthylphenyl)-1,1'-bi-2-naphthol (BTFP-BINOL) affords the corresponding tertiary alcohols in high enantioselectivities and yields. The reaction can also start with furan and 2-thienyllithium. The method is operationally simple and can be conducted on a 10-mmol scale without any difficulties.

Citation A. Matsuda; T. Ushimaru; Y. Kobayashi; T. Harada.Practical Method for the Catalytic Enantioselective Arylation and Heteroarylation of Ketones with Organotitanium Reagents Generated in situ from Bromide and Heteroarene Precursors.. Chemistry. 2017. doi:10.1002/chem.201701395

Related Elements

Titanium

See more Titanium products. Titanium (atomic symbol: Ti, atomic number: 22) is a Block D, Group 4, Period 4 element with an atomic weight of 47.867. The number of electrons in each of Titanium's shells is [2, 8, 10, 2] and its electron configuration is [Ar] 3d2 4s2. Titanium Bohr ModelThe titanium atom has a radius of 147 pm and a Van der Waals radius of 187 pm. Titanium was discovered by William Gregor in 1791 and first isolated by Jöns Jakob Berzelius in 1825. In its elemental form, titanium has a silvery grey-white metallic appearance. Titanium's properties are chemically and physically similar to zirconium, both of which have the same number of valence electrons and are in the same group in the periodic table. Elemental TitaniumTitanium has five naturally occurring isotopes: 46Ti through 50Ti, with 48Ti being the most abundant (73.8%). Titanium is found in igneous rocks and the sediments derived from them. It is named after the word Titanos, which is Greek for Titans.

Bromine

See more Bromine products. Bromine (atomic symbol: Br, atomic number: 35) is a Block P, Group 17, Period 4 element. Its electron configuration is [Ar]4s23d104p5. The bromine atom has a radius of 102 pm and its Van der Waals radius is 183 pm. In its elemental form, bromine Bromine Bohr Model has a red-brown appearance. Bromine does not occur by itself in nature; it is found as colorless soluble crystalline mineral halide salts. Bromine was discovered and first isolated by Antoine Jérôme Balard and Leopold Gmelin in 1825-1826.

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