Transition metal-free direct nucleophilic α-substitution of Morita–Baylis–Hillman alcohols with amines and thiols

Metal catalyst-free N-Allylation/alkylation of Imidazole and Benzimidazole with Morita-Baylis-Hillman (MBH) alcohols and acetates

“…In addition, a literature survey showed that nucleophilic allylic substitution reactions of acyclic/cyclic MBH adducts 1, 4, or 5, bearing good or poor leaving groups, using imidazole derivatives as nucleophilic reagents, have not been extensively developed. Therefore, in continuation of our previous study on the nucleophilic allylic substitution of MBH adducts [23][24][25][26], we disclose in this work a simple and efficient procedure for the synthesis of N-substituted imidazoles 6-8. The products were obtained either through direct conversions of the corresponding cyclic MBH alcohols 4 as well as acetates 5 in the presence of imidazoles 2a and 2b as nucleophilic reagents without catalysts or activating agents (Scheme 1, reaction 2), or from acyclic MBH alcohols 1 using DABCO as a powerful nucleophilic additive (Scheme 1, reaction 3).…”

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

“…In addition, a literature survey showed that nucleophilic allylic substitution reactions of acyclic/cyclic MBH adducts 1 , 4 , or 5 , bearing good or poor leaving groups, using imidazole derivatives as nucleophilic reagents, have not been extensively developed. Therefore, in continuation of our previous study on the nucleophilic allylic substitution of MBH adducts [ 23 – 26 ], we disclose in this work a simple and efficient procedure for the synthesis of N-substituted imidazoles 6 – 8 . The products were obtained either through direct conversions of the corresponding cyclic MBH alcohols 4 as well as acetates 5 in the presence of imidazoles 2a and 2b as nucleophilic reagents without catalysts or activating agents ( Scheme 1 , reaction 2), or from acyclic MBH alcohols 1 using DABCO as a powerful nucleophilic additive ( Scheme 1 , reaction 3).…”

“…Correlatively, we have previously reported a direct amination of cyclic MBH alcohols 4 with morpholine in the presence of imidazole ( 2a ), as a powerful nucleophilic additive, affording, via competitive allylic nucleophilic substitution in toluene at reflux, a mixture of the corresponding N-substituted morpholine and N-substituted imidazole derivatives 6 [ 23 ]. In addition, a literature survey showed that nucleophilic allylic substitution reactions of acyclic/cyclic MBH adducts 1 , 4 , or 5 , bearing good or poor leaving groups, using imidazole derivatives as nucleophilic reagents, have not been extensively developed.…”