4905
Much progress has been successfully achieved in the asymmetric reduction of imines , enamines , olefins , ketones and heteroarenes .
 imines, enamines, olefins, ketones, heteroarenes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 imines, enamines, olefins, ketones, heteroarenes