First [4+2] Cycloadditions Involving the Olefinic Bond of an ‘Aldoketeniminium Salt’ (=N-Alk-1-enylideneaminium Salt)
作者:Florence Mahuteau-Betzer、Ping-Yu Ding、Léon Ghosez
DOI:10.1002/hlca.200590154
日期:2005.7
‘Keteniminium triflates’ (=N-alk-1-enylideneaminium trifluoromethanesulfonates; [MeN(Ts)CHC NR1(R2)]+TfO−) generated in situ from Nα-tosylsarcosinamides MeN(Ts)CH2CONR1(R2) unexpectedly react with cyclopenta-1,3-diene and cyclohexa-1,3-diene to give Diels–Alder reactions across the CC bond of the cumulene. The use of Nα-tosylsarcosinamides derived from chiral pyrrolidines allows the direct preparation
'三氟甲磺酸酯Keteniminium'(= ñ -alk -1- enylideneaminium三氟甲; [男子(TS)CHC NR 1(R 2)] + TFO - )产生的原位从Ñ α -tosylsarcosinamides男性(Ts)的CH 2 CONR 1(R 2)意外地与环戊-1,3-二烯和环己-1,3-二烯反应,在异丙苯的CC键上产生Diels-Alder反应。使用ñ α从手性吡咯烷衍生-tosylsarcosinamides允许直接制备trinorbornenone衍生物的6在高对映体纯度。