209216-57-9Relevant articles and documents
Synthesis of protected derivatives of 3-pyrrolylalanine
Beecher, Jody E.,Tirrell, David A.
, p. 3927 - 3930 (2007/10/03)
Protected derivatives of 3-pyrrolylalanine (3-PA) have been synthesized starting with N-tri(isopropyl)silylpyrrole. Following formylation and Boc protection, treatment with (±)-N-(benzyloxycarbonyl)-α-phosphonoglycine trimethyl ester provided a fully protected dehydro-3-pyrrolylalanine. Reduction of the double bond and removal of the methyl ester groups yielded 3-PA protected at the α- and pyrrole nitrogens. 3-PA is only transiently stable following N-deprotection.
Divergent pathways in the intramolecular reactions between rhodium-stabilized vinylcarbenoids and pyrroles: Construction of fused tropanes and 7-azabicyclo[4.2.0]octadienes
Davies, Huw M. L.,Matasi, Julius J.,Ahmed, Gulzar
, p. 2305 - 2313 (2007/10/03)
The rhodium(II)-catalyzed intramolecular reaction between vinyldiazomethanes and pyrroles leads to a novel synthesis of fused tropanes. The reaction occurs by a stepwse 3 + 4 annulation mechanism between a rhodium-stabilized vinylcarbenoid intermediate and the pyrrole rather than by the typical tandem cyclopropanation/Cope rearrangement sequence. The outcome of the reaction is very sensitive to the vinylcarbenoid structure. In particular, the presence of a 2-siloxy substituent on the vinylcarbenoid strongly favors the formation of fused tropanes. In the absence of such functionality, the formation of fused 7-azabicyclo[4.2.0]octadienes becomes the dominant reaction pathway.
