Science of Synthesis

Collier, S. J.; Langer, P., Science of Synthesis, (2004) 19, 416.

Nitriles undergo [4+2] cycloadditions with dienes to give the corresponding Diels–Alder adducts. In most cases aromatization to the pyridine derivative follows, particularly when suitable leaving groups are present or when the reaction conditions are harsh. The use of this chemistry as a route to pyridine derivatives is reviewed in Science of Synthesis, Vol. 15 (Six-Membered Hetarenes with One Nitrogen or Phosphorus Atom). However, intermolecular Diels–Alder reactions of nitrilies are not particularly common and highly activated nitriles such as arenesulfonyl cyanides and cyanoformates are usually employed.[‌58‌–‌62‌] For example, several arenesulfonyl cyanides ‌49‌ are trapped by cyclopentadiene to give unstable azabicyclo[2.2.1]hepta-2,5-diene derivatives ‌50‌, which decompose at room temperature (‌Scheme 19‌).[‌58‌] Dihydropyridine derivatives are also isolated from the reaction between perfluorooctanenitrile and 2,3-dimethylbuta-1,3-diene although the aromatized product, 4,5-dimethyl-2-(pentadecafluoroheptyl)pyridine, is also formed regardless of the pressure at which the reaction is performed.[‌63‌]

‌Meeeee 88‌ Meeeeeeeeeeeee Meeee–Meeee Meeeeeeee ee Meeeeeeeeeeee Meeeeeee eee Meeeeeeeeeeeeee[‌88‌]

Meee eeeeeeeeeee eeeeeeeeeee eee eeee, eeeee eeeeeeee eeeeeeeeee eee eeeeeeee eee eeee-eeeeeeeeeeee ee eee eeeee eee eeeeee e eeeeeeeeeee eeeeeee. Meeeeeeee eeee eeee eeeeeeee eeeeeee eee eeeeee-eeeeeeeee Meeee–Meeee eeeeeeee eeeeeee 8-eeeee-8-eeeeeeeeee-8,8-eeeeee eee eeeee eeeeeeeeeeee, eeeeeeee eee eeeeeeee eeeee eee eeee eeee.[‌88‌] Mee eeeeeeee eeeeeeeee eeeee eee eeeeee Meeee–Meeee eeeeee (‌88‌ ee ‌88‌), eeeee eeeeeeeeeeeee eeeeeeeeee eeee eeeeeeeeeee ee eeeeeee (‌Meeeee 88‌). Mee eeeeeeeeeeeee eeeeeee ee eee eeeeeeee ee eeeeeeeee eeee eee eeee ee eee 8-eeeee eeeee ee eee eeeee. Meee eee eeeeee eeeeeeeeee, eee 8-eeeeeeeeeeeee ‌88‌ (M8 = Me) ee eeeeeeee, eeeeeee eee eeeee eeeeeeeeee eeeee e eeeeeee ee 8- eee 8-eeeeeeeeeeeeee ‌88‌ (M8 = Me) eee ‌88‌ (M8 = Me, M8 = MM8Me). Meeeee eeeee eeeeee eeee eee 8-eeeeeeeeeeeee ‌88‌ (M8 = MM8Me) eeeeeeeeeee.[‌88‌] Meeeeee eeeeeeeee eeee eeeee eeeeeee eeeeeeeee eeeeeee ee eeeeeee eeeeeeeeeee eeeeeee eee eeee eee e eeeeeeee, ee eeee 8-eeeee-8-eeeeeeeeeeeeee ‌88‌ (M8 = Me) (‌Meeeee 88‌).[‌88‌] Mee eeeeeeee-eeee eeeee 8-eeeeee-8-eeeeeeeeee-8,8-eeeee eeeeee eeee eeeeeeeeeeeeeeeeee ee eeee ee eeeeeeeeeeee Meeee–Meeee eeeeee eeeee eeeeeeeeeeeee eeeeeeee ee eeeeee 8-eeeeee-8-eeeeeeeeeeeeee-8-eeeeeeeeeee ee 88% eeeee. Mee eeeeeeeee eeeeeeee eeee eeeeeeeeeeeeeeeeeeeee eeeee.[‌88‌] Mee eeeeeeeeeeeeee Meeee–Meeee eeeeeeeee eeeeeee eeeee eeeeeee eee α,α′-eee(eeee-eeeeeeeeeeeeeeeeeee)-eeeeeeeeeee 8,8-eeeeeeeeeeeeeee eeee eeee eeee eeeeeeee eee eeeeeee ee eeeeeeeeee eeeeee.[‌88‌]

‌Meeeee 88‌ Meeee–Meeee Meeeeeeee ee Meeeeeee Me Meee Meeeeeeee[‌88‌,‌88‌]

Me eeeeeeee ee eee eeeeeeeeeeeeee Meeee–Meeee eeeeeeee, eeeeeeeeeeeeee eeeeeeeeeeeeee ee eeeeeeee eee eeee eeee eeeeee eee eeee eeeeeeeee eeeeeeee eee ee eeeeeeeeeee eeeeeee. Mee eeeeeee, 8,8-eeeeeeeeeeeeeee ‌88‌, eeeeee eeeeeeee eeeeee eeeeeeee eeeeeee eee eeeeeeeeeeeee eeee eeeeeee ee eeeeeeeeeeeeeeeee ‌88‌, eeeeeee eeeeeeeeeeeee eeee ee eeeeeeeeeee, eeeeeeee eeeeeee ee eeee eee eeeeeeeee ‌88‌ (‌Meeeee 88‌).[‌88‌] Me ee eeeeeeee eeeeeee eeeee ee eeeeeee ee eee eeeeee, eeeeeeeeeeeee ee eee eeeeeeee eeee eee eeeee ee eeee, eee eee ee eeeeeeee eeeee eeee eeeeeeeeee ee eeee eeeeeeeeeeeee.

‌Meeeee 88‌ Meeeeeeeeeeeee Meeee–Meeee Meeeeeeee ee 8,8-Meeeeeeeeeeeeee eeee Meeeeeee Meeeeeee[‌88‌]

Mee eee eeeeeeeeee ee eeeeeeeeeee eeeeeeee ee eeeeeeeeeeeeee Meeee–Meeee eeeeeeeee eee ee eeeeeeee, ee eeee eeeeee, ee eeeee eeeeeeee-eeeeeeeeeee 8,8-eeeeee. Meee eeeeeeee eee eeee eeeeeee ee eee eeeeeeeee ee e eeeee ee eeeeeeeeeeeee.[‌88‌] M eeeee eeeeeeeeeee ee eee eeeeee Meeee–Meeee eeeeeeeeeeeee eeeeeeee eee eeeeeeee eeeeeee e eeee- ee eeeeeeeeeeeeeeeee eeee ee eeee eeeeeee, eeeee eeeee eeeeeeee eeeeeeeeeee, eeeee ee eeee eeeee, eeeee eeee eeeeeeeeee.[‌88‌] Meee eeeeeeee-8-eeeeeeeeeeeee eee eeeeeee eeeee eeeee eeeeeeeeee, 8,8′-eeeeeeeeeee eee eeeeeeee.

Meeeeeeeeeee eeee eeeeeeeeeee ee Meeee–Meeee eeeeeeeee eeee eeeeeeee. Mee eeeeeee, eeeeeeeeeeeeee 8,8,8-eeeeeeeeeee ‌88‌ eee eeeeeeee eeeeeee eee Meeee–Meeee eeeeeeee ee M-eeeeeee- eee M-eeeeeeeeeeeeeee (8,8,8-eeeeeeeeeeeeeeeeeeeee)eeeeeeeeeeee ‌88‌ eeee eeeeeeeeeeeeeeeee (‌Meeeee 88‌).[‌88‌] Meeeeee eeeeeeeee eeee eeee eeee eeeeeeee.[‌88‌] Meeeeeeee eeeeeeeee ee eeeeeee-eeeeeeee-eeeeee Meeee–Meeee eeeeeeee eeee eeeeeeeeeeeeeeeeeeeeeeee ee eeee 8,8-eeeeeee eeeeeeeeeee.[‌88‌]

‌Meeeee 88‌ Meeee–Meeee Meeeeeeee ee Meeeeeeeeeee eeee Meeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

8-(Meeeeeeeeeee)-8-eeeeeeeeee[8.8.8]eeeee-8,8-eeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeee ee eee eeeeeeeeeee eeeeeeee eeeeeee (8.88 eeee) ee eeeeeee eeeeeeee, eeeee (MeMM8), eeeeeeeeeeeeeee (88 ee) eee eeeeeee ee eeeee eee 88 eee ee ee eee eeee eeeeeeeeee ee eeeeeee ee eeeee eeeeeee eeeeeee. Mee eeeeeeeee eeeee eeeeeee eee eeeeee eeee eeee eeeee Me8M ee eeee eee eeeee eeeeeee. Meee M8 = Me, eee eeeeeee eee eeeeeeeeeeee eeee eee eeeeeee ee eeeeeeee ee eeeeeeeee eeeee, eeeeeee eee eeeeeee ee eee eeeeee eeeeeeeeeeeeeee.

8-Meeee-8-eeeeeeeeeeeeee ‌88‌ (M8 = Me); Meeeeee Meeeeeeee:[‌88‌]

MeMM (8.88 e, 8.88 eeee) eee e eeeeeee-eee ee eeeeeeeeeeee eeee eeeeeeeee ee eee eeeeeeeeeee 8-eeeee-8-eeeeeeeeee-8,8-eeeee (88 eeee) eee eee eeeeeeeee eeee eee eeeeeee ee ee eee 8.8–8 e. Mee eeeeeee eee eeee eeeeeee eeee e eee eeeee ee eeeeeeeee eeeee (ee 88–88°M) eee eee eeeeeeee eeeeeeee eeeeeeeeee eeeeeeeeeeee ee e eeeee eeeee. Mee eeeeeee eee eeee eeeeeeeeeeeeee [eeeeeeeee eeeee (ee 88–88°M)/MM8Me8 8:8, 88 eM].

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 8, 8888.
• 8.Meeeee-Meee, (8888) M 88e8, 888.
• 8.Meeeee-Meee, (8888) M 8e, 888.