Aminomethyl Transfer (Mannich) Reactions Between an O‐Triethylsilylated Hemiaminal and Anilines, R n C 6 H 5− n NH 2 Leading to New Diamines, Triamines, Imines, or 1,3,5‐Triazines Dependent upon Substituent R

The reactions of the Mannich reagent Et 3 SiOCH 2 NMe 2 ( 1 ) with a variety of anilines (mono‐substituted RC 6 H 4 NH 2 , R=H, 4‐CN, 4‐NO 2 , 4‐Ph, 4‐Me, 4‐MeO, 4‐Me 2 N; di‐substituted R 2 C 6 H 3 NH 2 , R 2 =3,5‐(CH 3 ) 2 , 3,5‐(CF 3 ) 2 ; tri‐substituted R 3 C 6 H 2 NH 2 , R 3 =3,5‐Me 2 ‐4‐Br and a “super bulky” aniline (Ar*NH 2 ) [Ar*=2,6‐bis(diphenylmethyl)‐4‐ tert ‐butylphenyl]) led to the formation of a range of products dependent upon the substituent. With electron‐withdrawing substituents, previously unknown diamines, RC 6 H 4 NH(CH 2 NMe 2 ) [R=CN ( 2 a ), NO 2 ( 2 b )] and R 2 C 6 H 3 NH(CH 2 NMe 2 ) [R 2 =3,5‐(CF 3 ) 2 ( 2 c) ] were formed. Further reaction of 2 a , b , c with 1 yielded the corresponding triamines RC 6 H 4 N(CH 2 NMe 2 ) 2 (R=CN ( 3 a ), NO 2 ( 3 b ) and R 2 C 6 H 3 N(CH 2 NMe 2 ) 2 , R 2 =3,5‐(CF 3 ) 2 ( 3 c ). The new polyamines were characterized by NMR spectroscopy, and for 2 a , 2 c , and 3 c , by single crystal XRD. In the case of electron‐donating groups, R=4‐OMe, 4‐NMe 2 , 4‐Me, 3,5‐Me 2 , 3,5‐Me 2 ‐4‐Br, and for R=4‐Ph, the reactions with 1 immediately led to the formation of the related 1,3,5‐triazines, R=4‐MeO ( 5 a ), 4‐Me 2 N ( 5 b ), 4‐Me ( 5 c ), 3,5‐Me 2 ( 5 d ), 3,5‐Me 2 ‐4‐Br ( 5 e ), 4‐Ph ( 5 f ), 4‐Cl ( 5 g ). The “super bulky” aniline rapidly produced a single product, namely the corresponding imine Ar*N=CH 2 ( 4 ) which was also characterized by single crystal XRD. Imine 4 is both thermally and oxidatively stable. All reactions are very fast, thus based upon the presence of Si we are tempted to denote the reactions of 1 as examples of “Silick” chemistry.