Preparing N-heterocyclic carbene compound, useful e.g. as catalysts, comprises deprotonating amidine compound to give amidinium salt, followed by reacting the salt with allylic compound, cyclizing and reacting with strong base

摘要

Preparation of N-heterocyclic carbene compound (I) comprises: (a) deprotonation of an amidine compound (II) in the presence of a strong base, which is sodium- or potassium base to give a sodium or potassium amidinium salt (III); (b) reaction of (III) with an allylic compound (IV) to give an allylic amidine compound (V); (c) cyclization of (V) to give an imidazolium salt (VI); and (d) converting (VI) into (I) by reaction with the strong base. Preparation of a N-heterocyclic carbene compound of formula (I) comprises: (a) deprotonation of an amidine compound of formula (R 2-N=CH-NH-R 1) (II) in the presence of a strong base, which is sodium- or potassium base to give a sodium or potassium amidinium salt of formula (R 2-N=CH-N --R 1)(M +) (III); (b) reaction of (III) with an allylic compound of formula (X-C(R 6)(R 7)-C(R 3)=C(R 5)-R 4) (IV) to give an allylic amidine compound of formula (R 2-N=CH-N(R 1)-C(R 6)(R 7)-C(R 3)=C(R 5)-R 4) (V); (c) cyclization of (V) to give an imidazolium salt of formula (VI); and (d) converting (VI) into (I) by reaction with the strong base. R 1, R 2hydrocarbon chain (optionally partially or completely cyclic and optionally substituted); R 3-R 5H, alkyl or R 1; R 6, R 7H, alkyl or hydrocarbon chain (optionally partially or completely cyclic); M : Na or K; X : leaving group comprising Cl, Br or sulfonic ester group; and A -anion, preferably chloride or bromide anion. An independent claim is included for the preparation of (VI) comprising steps (a)-(c). [Image].