A process for preparing a 1,2-diol, the process comprising contacting an ester of the formulas or: with an anhydrous C 2 -C 12 alcohol in the presence of a catalyst of the formula: in a reactor at ambient pressure and elevated temperature for a time sufficient to form a 1,2-diol, wherein R 1 and R 2 are each independently an alkyl, aryl, alkoxy, aryloxy, dialkylamido, diarylamido, or alkylarylamido group having 1 to 12 carbon atoms; R 3 and R 4 are each independently an alkyl or aryl group having 1 to 12 carbon atoms, if E is nitrogen; R 3 and R 4 are each independently an alkyl, aryl, alkoxy, aryloxy, dialkylamido, diarylamido, or alkylarylamido group having 1 to 12 carbon atoms, if E is phosphorus; R 1, R 2, and P may be connected to form a 5 or 6-membered heterocyclic ring; R 3, R 4, and E may be connected to form a 5 or 6-membered heterocyclic ring; R 5 and R 6 are each independently a C 1 -C 6 alkylene or arylene group; E is phosphorus or nitrogen; L is a neutral ligand; R 10 is an alkyl or aryl group having 1 to 20 carbon atoms; R 11 is each independently hydrogen, or an alkyl or aryl group having 1 to 20 carbon atoms; and R 12 is hydrogen, or an alkyl, aryl, alkoxy, or aryloxy group having 1 to 20 carbon atoms, wherein "alkyl" refers to straight, branched, or cyclic alkyl groups, wherein "aryl" generally refers to phenyl or naphthyl, but in connection with R 10 and R 11 "aryl" includes not only phenyl and naphthyl but also other hydrocarbon rings containing alternating single and double bonds, wherein one or more of R 1, R 2, R 3, and R 4 may be substituted with one or more groups selected from methoxy, ethoxy, isopropoxy, dimethylamido, diethylamido, and diisopropylamido. with an anhydrous C 2 -C 12 alcohol in the presence of a catalyst of the formula: in a reactor at ambient pressure and elevated temperature for a time sufficient to form a 1,2-diol, wherein R 1 and R 2 are each independently an alkyl, aryl, alkoxy, aryloxy, dialkylamido, diarylamido, or alkylarylamido group having 1 to 12 carbon atoms; R 3 and R 4 are each independently an alkyl or aryl group having 1 to 12 carbon atoms, if E is nitrogen; R 3 and R 4 are each independently an alkyl, aryl, alkoxy, aryloxy, dialkylamido, diarylamido, or alkylarylamido group having 1 to 12 carbon atoms, if E is phosphorus; R 1, R 2, and P may be connected to form a 5 or 6-membered heterocyclic ring; R 3, R 4, and E may be connected to form a 5 or 6-membered heterocyclic ring; R 5 and R 6 are each independently a C 1 -C 6 alkylene or arylene group; E is phosphorus or nitrogen; L is a neutral ligand; R 10 is an alkyl or aryl group having 1 to 20 carbon atoms; R 11 is each independently hydrogen, or an alkyl or aryl group having 1 to 20 carbon atoms; and R 12 is hydrogen, or an alkyl, aryl, alkoxy, or aryloxy group having 1 to 20 carbon atoms, R 1 and R 2 are each independently an alkyl, aryl, alkoxy, aryloxy, dialkylamido, diarylamido, or alkylarylamido group having 1 to 12 carbon atoms; R 3 and R 4 are each independently an alkyl or aryl group having 1 to 12 carbon atoms, if E is nitrogen; R 3 and R 4 are each independently an alkyl, aryl, alkoxy, aryloxy, dialkylamido, diarylamido, or alkylarylamido group having 1 to 12 carbon atoms, if E is phosphorus; R 1, R 2, and P may be connected to form a 5 or 6-membered heterocyclic ring; R 3, R 4, and E may be connected to form a 5 or 6-membered heterocyclic ring; R 5 and R 6 are each independently a C 1 -C 6 alkylene or arylene group; E is phosphorus or nitrogen; L is a neutral ligand; R 10 is an alkyl or aryl group having 1 to 20 carbon atoms; R 11 is each independently hydrogen, or an alkyl or aryl group having 1 to 20 carbon atoms; and R 12 is hydrogen, or an alkyl, aryl, alkoxy, or aryloxy group having 1 to 20 carbon atoms, wherein "alkyl" refers to straight, branched, or cyclic alkyl groups, wherein "aryl" generally refers to phenyl or naphthyl, but in connection with R 10 and R 11 "aryl" includes not only phenyl and naphthyl but also other hydrocarbon rings containing alternating single and double bonds, wherein one or more of R 1, R 2, R 3, and R 4 may be substituted with one or more groups selected from methoxy, ethoxy, isopropoxy, dimethylamido, diethylamido, and diisopropylamido.