Regioselectivity in Reactions between Bis(2-benzothiazolyl)ketone and Vinyl Grignard Reagents: C- versus O-alkylation-Part III.

Title Regioselectivity in Reactions between Bis(2-benzothiazolyl)ketone and Vinyl Grignard Reagents: C- versus O-alkylation-Part III.
Authors C. Boga; S. Bordoni; L. Casarin; G. Micheletti; M. Monari
Journal Molecules
DOI 10.3390/molecules23010171
Abstract

The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2-methyl-1-propenylmagnesium bromide was carried out under different experimental conditions and in the presence of radical scavengers. The results indicate a plausible mechanistic pathway involving radical intermediates in the case of O-alkylation, but a polar ones in the case of classic C-alkylation. This agrees with our previous reports indicating a key role played by the delocalization ability of the substituents bound to the carbonyl group in driving the regioselectivity of the vinylmagnesium bromide attack towards O-alkylation. Further support of this was obtained by diffractometric analysis of four distinct bis(heteroaryl)ketones.

Citation C. Boga; S. Bordoni; L. Casarin; G. Micheletti; M. Monari.Regioselectivity in Reactions between Bis(2-benzothiazolyl)ketone and Vinyl Grignard Reagents: C- versus O-alkylation-Part III.. Molecules. 2018;23(1). doi:10.3390/molecules23010171

Related Elements

Magnesium

Magnesium Bohr ModelSee more Magnesium products. Magnesium (atomic symbol: Mg, atomic number: 12) is a Block S, Group 2, Period 3 element with an atomic mass of 24.3050. The number of electrons in each of Magnesium's shells is [2, 8, 2] and its electron configuration is [Ne] 3s2. The magnesium atom has a radius of 160 pm and a Van der Waals radius of 173 pm. Magnesium was discovered by Joseph Black in 1775 and first isolated by Sir Humphrey Davy in 1808. Magnesium is the eighth most abundant element in the earth's crust and the fourth most common element in the earth as a whole. Elemental MagnesiumIn its elemental form, magnesium has a shiny grey metallic appearance and is an extremely reactive. It is can be found in minerals such as brucite, carnallite, dolomite, magnesite, olivine and talc. Commercially, magnesium is primarily used in the creation of strong and lightweight aluminum-magnesium alloys, which have numerous advantages in industrial applications. The name "Magnesium" originates from a Greek district in Thessaly called Magnesia.

Related Forms & Applications