Annulations of enantioenriched allenylsilanes with in situ generated iminium ions: stereoselective synthesis of diverse heterocycles.
Highly enantioenriched allenylsilanes participate in Lewis acid mediated annulations with in situ generated iminium ions derived from tert-butyl carbamate and methyl carbamate to selectively form functionalized 4,5-dihydropyrroles and 4,5-dihyrooxazines, respectively. The dihydropyrrole products were further elaborated in a stereocontrolled vinylsilane terminated cyclization with in situ generated oxonium ions, resulting in pyranopyrroles.
Brawn
Ryan A
RA
Department of Chemistry, Metcalf Center for Science and Engineering, 590 Commonwealth Avenue, Boston University, Boston, Massachusetts 02215, USA.
Panek
James S
JS
D000447:Aldehydes / Q000737:chemistry; D002219:Carbamates / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity
D000447:Aldehydes; D002219:Carbamates; D006571:Heterocyclic Compounds; D007097:Imines; D012821:Silanes