?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F7585%2F&rft.title=Catalytic%2C+Asymmetric+Synthesis+of+%C3%A2-Lactams+with+Cinchona+Alkaloid+Catalysts&rft.creator=Xu%2C+Xuan&rft.description=In+2004%2C+our+group+found+with+TMS+protected+quinine+and+quinidine+as+catalysts%2C+%EF%81%A2-lactones+can+be+synthesized+with+high+diastereoselectivity+and+enantioselectivity+by+acyl-halide+aldehyde+cyclocondensation+(AAC)+reactions+(Scheme+I).+Based+on+the+success+of+AAC+methodology+in+our+group%2C+we+want+to+check+the+potential+for+the+application+of+the+same+protocol+in+the+asymmetric+%C3%A2-lactam+synthesis+(Scheme+II).+Instead+of+aldehyde%2C+imines+will+be+chosen+as+substrates+for+the+%5B2%2B2%5D+cycloaddition.+We+want+to+know+that+with+some+activation+group+at+nitrogen+atom%2C+whether+we+can+get+some+active+substrates.+In+addition%2C+if+the+imine+substrates+are+not+very+active%2C+would+Lewis+acid+provide+sufficient+activations+to+imines%3F+If+the+substituted+ketenes+are+substrates%2C+what+would+the+diastereoselectivity+be%3F+The+activation+group+at+N+atom+was+chosen+as+nitrobenzenesulfonyl+group+and+the+R1+substituent+can+be+aromatic+groups+(Scheme+III).+The+yields+and+ee+values+were+good.+In+this+project%2C+we+extend+the+successful+protocol+in+AAC+chemistry+to+the+asymmetric+%C3%A2-lactam+synthesis.+In+our+system%2C+benzenesulfonyl+group+is+proved+to+be+a+good+choice+of+activation+group.+Because+of+the+small+energy+difference+in+the+transition+state+for+the+reaction+between+alkyl+group+substituted+ketene+and+activated+imine+substrate%2C+low+diastereoselectivity+was+obtained.&rft.date=2006-06-29&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F7585%2F1%2FXuX_edtPitt2006.pdf&rft.identifier=++Xu%2C+Xuan++(2006)+Catalytic%2C+Asymmetric+Synthesis+of+%C3%A2-Lactams+with+Cinchona+Alkaloid+Catalysts.++Master's+Thesis%2C+University+of+Pittsburgh.++++(Unpublished)++