Vitamin B-1 as a metal-ion-free natural catalyst for sustainable quinoxaline ring condensation under sonochemical conditions

作者：Aghapoor Kioumars; Mohsenzadeh Farshid; Talebian Shiva; Tehrani Mohammad Jafar; Balavar Yadollah; Kh****izadeh Golriz; Darabi Hossein Reza^*

来源：Monatshefte fur Chemie, 2011, 142(6): 619-624.

DOI：10.1007/s00706-011-0487-5

• Vitamin B-1
• Metal-ion-free natural catalyst
• Quinoxalines
• Ultrasonic irradiation

The role of vitamin B-1 as a catalyst is investigated for the quinoxaline ring condensation under various mild reaction conditions. The results revealed that the combination of vitamin B-1 and ultrasonic irradiation promotes the reaction more efficiently. The salient features of this environmentally benign method are fast conversions, excellent yields for a wide range of substrates, and the use of a low-cost, readily available, nontoxic, and metal-ion-free natural catalyst. The wide range of turnover frequency values (6-400 h(-1)) shows that the reaction rate is highly dependent on the nature of the functional groups on the aromatic ring of substrates. Moreover, a plausible mechanism for the catalytic action of vitamin B-1 has been introduced.

• 出版日期2011-6