Philip E Sonnet

Learn More
[reaction: see text] Azabicycle 4 and sec-butyllithium/TMEDA afford the C(1) bridgehead alpha-lithio anion at 0 degrees C. Anion quenching with carbon dioxide, methyl chloroformate, or DMF provide the bridgehead acid 8a (N-BOC-2,4-methanoproline), ester 8b, or aldehyde 8c, respectively. By contrast, at -78 degrees C these same reagents give a mixture of(More)
The reactions of N-(alkoxycarbonyl)-2-azabicyclo[2.2.0]hex-5-enes 5 with halonium ion electrophiles were studied in polar and nonpolar aprotic solvents and also in protic media with the aim of controlling nitrogen neighboring group participation. Specifically, for bromonium ions nitrogen participation is facilitated by the polar aprotic solvent nitromethane(More)
Additions of iodonium-X reagents to N-alkoxycarbonyl-2-azabicyclo[2.2.1]hept-5-enes and the homologous 2-azabicyclo[2.2.2]oct-5-enes have been found to mirror the outcomes of additions of bromonium-X reagents. Only rearranged products were observed for reactions of either of these halonium ion reagents with the azabicylo[2.2.1]hept-5-enes. For the(More)
CD spectra for homooligomers (n = 4, 6, 8) of (1S,4R,5R)-5-syn-carboxy-2-azabicyclo[2.1.1]hexane (MPCA), a methano-bridged pyrrolidine β-carboxylic acid, suggest an ordered secondary structure. Even in the absence of internal hydrogen bonding, solution NMR, X-ray, and in silico analyses of the tetramer are indicative of conformations with trans-amides and(More)
The ability of Selectfluor to act as a nucleofuge for hydrolysis of beta-anti-halides was investigated with N-alkoxycarbonyl derivatives of 6-anti-Y-7-anti-X-2-azabicyclo[2.2.1]heptanes and 4-anti-Y-8-anti-X-6-azabicyclo[3.2.1]octanes. The azabicycles contained X = I or Br groups in the methano bridge and Y = F, Br, Cl, or OH substituents in the larger(More)
N-acetylmethanopyrrolidine methyl ester and its four 5-syn/anti-fluoro and hydroxy derivatives have been synthesized from 2-azabicyclo[2.2.0]hex-5-ene, a 1,2-dihydropyridine photoproduct. These conformationally constrained mimics of idealized C(β)-gauche and C(β)-anti conformers of pyrrolidines were prepared in order to determine the inherent bridge bias(More)
Proline derivatives with a C(γ)-exo pucker typically display a high amide bond trans/cis (K(T/C)) ratio. This pucker enhances n→π* overlap of the amide oxygen and ester carbonyl carbon, which favors a trans amide bond. If there were no difference in n→π* interaction between the ring puckers, then the correlation between ring pucker and K(T/C) might be(More)
[reaction: see text] The first syntheses of 5,6-difunctionalized-2-azabicyclo[2.1.1]hexanes containing syn-hydroxy and syn-fluoro substituents have been effected in a stereocontrolled manner. The key reactions are regioselective additions to the aziridinium ions formed from 6-exo-iodo(bromo)-5-endo-X-2-azabicyclo[2.2.0]hexanes (X = F, OH) upon silver or(More)
The reaction that occurs when vapors of 2,2-dimethylpropanal and methanamine are allowed to mix in an infrared gas cell has been examined. The disappearance of starting materials and formation of E-imine product, monitored simultaneously, is best fit by a process involving wall-associated water. The same or closely related processes have been successfully(More)
A study of the reaction between gaseous aldehydes and amines has implicated proton transfer from wall-associated water. Carbinolamine formation and subsequent dehydration to imine with assistance by wall associated hydroxyl bearing species has not previously been specifically suggested to obtain in the multitude of enzyme processes using pyridoxal cofactor.(More)