Shedding Light on the Diverse Reactivity of NacNacAl with N-Heterocycles.

Authors :: Dmitrienko A
Pilkington M
Britten JF
Gabidullin BM
van der Est A
Nikonov GI
Source :: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2020 Sep 07; Vol. 59 (37), pp. 16147-16153. Date of Electronic Publication: 2020 Jun 25.
Publication Year :: 2020
Abstract: The aluminum(I) compound NacNacAl (NacNac=[ArNC(Me)CHC(Me)NAr] <superscript>-</superscript> , Ar=2,6-iPr <subscript>2</subscript> C <subscript>6</subscript> H <subscript>3</subscript> , 1) shows diverse and substrate-controlled reactivity in reactions with N-heterocycles. 4-Dimethylaminopyridine (DMAP), a basic substrate in which the 4-position is blocked, induces rearrangement of NacNacAl by shifting a hydrogen atom from the methyl group of the NacNac backbone to the aluminum center. In contrast, C-H activation of the methyl group of 4-picoline takes place to produce a species with a reactive terminal methylene. Reaction of 1 with 3,5-lutidine results in the first example of an uncatalyzed, room-temperature cleavage of an sp <superscript>2</superscript> C-H bond (in the 4-position) by an Al <superscript>I</superscript> species. Another reactivity mode was observed for quinoline, which undergoes 2,2'-coupling. Finally, the reaction of 1 with phthalazine produces the product of N-N bond cleavage.<br /> (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)