Title Stereoselective Synthesis of β-Amino Ketones via Direct Mannich-Type Reaction Catalyzed with SO2-/TiO2 and SO2-/Nano TiO2 Type JournalPaper Keywords Not Registered! Abstract Not Registered! Researchers (Fourth Researcher), (Third Researcher), (Second Researcher), Bagher Eftekhari-Sis (Second Researcher)