620972-00-1Relevant articles and documents
Transformations of β-aryl-N-Cbz-α,β-didehydro-α-amino esters with hydrazine hydrate
Drev, Miha,Gro?elj, Uro?,Svete, Jurij
, p. 623 - 631 (2016)
Cyclizations of Cbz-protected α,β-didehydro-β-arylalanine esters 1 with excess hydrazine hydrate afforded mixtures of the expected 3-pyrazolidinones 2 and the unexpected 1-amino-5-benzylidenehydantoins 6 and N-Cbz-β-arylalanine hydrazides 7. Presumably, the pyrazolidinones 2 and hydantoins 6 are formed as primary products via competitive 1,2- and 1,4-addition of hydrazine hydrate followed by cyclization, whereas β-arylalanine hydrazides 7 are formed as secondary products via reductive cleavage of the C(5)-N(1) bond in pyrazolidinones 2. The overall selectivity depends on the reaction time and on the β-substituent in the starting dehydroalanine ester 1.
Stereoselective Intramolecular [4 + 3] Cycloadditions of Nitrogen-Stabilized Chiral Oxyallyl Cations via Epoxidation of N-Tethered Allenamides
Xiong, Hui,Huang, Jian,Ghosh, Sunil K.,Hsung, Richard P.
, p. 12694 - 12695 (2007/10/03)
The first intramolecular [4 + 3] cycloaddition reaction using nitrogen-stabilized chiral oxyallyl cations that are tethered to furan or diene through the nitrogen atom is described here. Formation of these nitrogen-stabilized chiral oxyallyl cations is ac
