The main-group Lewis superacid complexes(pin^(F))_(2)Si·MeCN(1·MeCN)and(pin^(F))_(2)Ge·MeCN(2·MeCN)were successfully applied as promoters in the catalytic reduction of phosphine oxides(e.g.,Me_(3)P...The main-group Lewis superacid complexes(pin^(F))_(2)Si·MeCN(1·MeCN)and(pin^(F))_(2)Ge·MeCN(2·MeCN)were successfully applied as promoters in the catalytic reduction of phosphine oxides(e.g.,Me_(3)PO,Bu_(3)PO,and Ph_(3)PO),a sulfoxide(i.e.,Me_(2)SO),and an amide(i.e.,Me_(2)NCHO)to furnish the respective phosphines,dimethyl sulfide,and trimethylamine using silanes(e.g.,PhSiH_(3)and(EtO)_(3)SiH)as hydrogen sources(pin^(F)=perfluoropinacolato).These substrates target difficult to reduce representatives of oxo compounds in comparison with,for example,the ketones or aldehydes often targeted in such types of catalytic reductions.As benchmark promoters,we also studied B(C_(6)F_(5))_(3)and HNTf_(2)as reference(soft)Lewis superacid and Brønsted superacid,respectively(Tf=SO_(2)CF_(3)).Among the combinations of(pre)catalyst,substrate,and reducing agent investigated,the silicon complex 1·MeCN turned out to be the most versatile system,being the by far most potent(DMSO)or just slightly underperforming(R_(3)PO and DMF)promoter.Moreover,the hitherto undescribed Lewis acid base adducts 1·Me_(2)NCHO and 2·Me_(2)SO were synthesized,isolated,and structurally investigated using NMR spectroscopy and single-crystal XRD analysis.展开更多
基金the European Research Council(ALLOWE101001591)for financial support。
文摘The main-group Lewis superacid complexes(pin^(F))_(2)Si·MeCN(1·MeCN)and(pin^(F))_(2)Ge·MeCN(2·MeCN)were successfully applied as promoters in the catalytic reduction of phosphine oxides(e.g.,Me_(3)PO,Bu_(3)PO,and Ph_(3)PO),a sulfoxide(i.e.,Me_(2)SO),and an amide(i.e.,Me_(2)NCHO)to furnish the respective phosphines,dimethyl sulfide,and trimethylamine using silanes(e.g.,PhSiH_(3)and(EtO)_(3)SiH)as hydrogen sources(pin^(F)=perfluoropinacolato).These substrates target difficult to reduce representatives of oxo compounds in comparison with,for example,the ketones or aldehydes often targeted in such types of catalytic reductions.As benchmark promoters,we also studied B(C_(6)F_(5))_(3)and HNTf_(2)as reference(soft)Lewis superacid and Brønsted superacid,respectively(Tf=SO_(2)CF_(3)).Among the combinations of(pre)catalyst,substrate,and reducing agent investigated,the silicon complex 1·MeCN turned out to be the most versatile system,being the by far most potent(DMSO)or just slightly underperforming(R_(3)PO and DMF)promoter.Moreover,the hitherto undescribed Lewis acid base adducts 1·Me_(2)NCHO and 2·Me_(2)SO were synthesized,isolated,and structurally investigated using NMR spectroscopy and single-crystal XRD analysis.
