A method of forming a N-substituted pyrrole of formula (1) that includes reacting an amine of formula (2) with a compound of formula (3) in the presence of a catalyst including juice from a fruit of a plant in the genus Malus, ##STR00001## R.sub.1 and R.sub.2 are each independently a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, or an optionally substituted aryl; or wherein R.sub.1 and R.sub.2 together form a five-, six-, or seven-membered ring with the carbon atoms to which they are attached; and R.sub.3 is a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted arylalkyl, or an optionally substituted aryl.

A method for making a pyrrole includes reacting an aryl amine with a hexadione compound in the presence of a juice catalyst that contains juice from a fruit of a plant in the genus Malus.

A method for making a pyrrole includes reacting an aryl amine with a hexadione compound in the presence of a juice catalyst that contains juice from a fruit of a plant in the genus Malus.

A compound of the following formula

##STR00001##

capable of binding to a tripartite motif (TRIM) protein E3 ubiquitin ligase (TRIM21). This application also provides a method for treating a disease associated with abnormal cell proliferation with the compound of formula (I). This application further provides a method for preparing a drug for targeted protein degradation with such compound as an intermediate.

A compound of the following formula

##STR00001##

capable of binding to a tripartite motif (TRIM) protein E3 ubiquitin ligase (TRIM21). This application also provides a method for treating a disease associated with abnormal cell proliferation with the compound of formula (I). This application further provides a method for preparing a drug for targeted protein degradation with such compound as an intermediate.