Tetrasubstituted Pyrrolidines via a Tandem Aza-Payne/Hydroamination Reaction
作者:Jennifer M. Schomaker、Andrea R. Geiser、Rui Huang、Babak Borhan
DOI:10.1021/ja068077w
日期:2007.4.1
A facile tandem aza-Payne/hydroamination reaction of aziridinol is reported, which yields highly functionalized pyrrolidines. Addition of alkynyl Grignards to 2,3-aziridinals yields, in most cases, high syn to anti ratios of the aziridinol. Treatment of the syn-aziridinol with base leads initially to an aza-Payne rearrangement, which juxtaposes the amine and the alkyne in favorable orientation to complete the hydroamination. The anti-aziridinol undergoes the aza-Payne rearrangement, but cannot proceed further with the hydroamination.
Pt(II)-Catalyzed Synthesis of 1,2-Dihydropyridines from Aziridinyl Propargylic Esters
作者:Massoud Motamed、Eric M. Bunnelle、Surendra W. Singaram、Richmond Sarpong
DOI:10.1021/ol070658i
日期:2007.5.1
Pt(II)-catalyzed cycloisomerization of aziridinyl propargylic esters affords 1,2-dihydropyridines with regiodefined installation of substituents. A mild conversion of the 1,2-dihydropyridines to the corresponding substituted pyridines as well as chirality retention from the aziridinyl propargylic ester substrates have been demonstrated.
The outcome of a tandem aza-Payne/hydroamination reaction is modified via the use of a latent nucleophile. The latter initially serves as an electrophile to intercept the aziridine alkoxide and afterward turns into a nucleophile thereby performing the aziridine ring opening, out competing the intramolecular aza-Payne pathway. Subsequent hydroamination in the same pot provides N-Ts enamide carbonates, which can be easily converted into biologically significant 3,4-dihydroxylactams.