Synthesis of several novel optically active nitroxyl radicals

Nitroxide decomposition: Implications toward nitroxide design for applications in living free‐radical polymerization

“…7 In organic chemistry, nitroxides have been used in kinetic studies, [8][9][10][11] as oxidizing species in the form of the corresponding N-oxo ammonium salts, [12][13][14][15][16][17][18][19][20][21][22][23] as temporary caps for transient carbon radicals, [24][25][26][27][28][29][30][31] and as probes for stereocontrol with prochiral carbon radicals. [32][33][34][35][36] In polymer chemistry, nitroxide-mediated polymerization (NMP) [37][38][39][40][41][42][43][44][45][46][47] has become popular as a method for preparing living polymers [48][49][50][51] under mild, chemoselective conditions with good control over both the polydispersity and molecular weight. In designing nitroxides for applications in NMP, much attention has been directed toward fine-tuning the nitroxide structure to lower the bond dissociation energy (BDE) of the transient Nalkox...…”

Synthesis of Multifunctional Ag@Au@Phenol Formaldehyde Resin Particles Loaded with Folic Acids for Photothermal Therapy

“…The synthesis of novel prolinamide–camphor organocatalysts 4 a – c begins with the Boc‐protected L ‐proline and trans ‐4‐hydroxy L ‐proline. Treatment of Boc L ‐proline and trans ‐4‐hydroxy L ‐proline with 1‐amino‐7,7‐dimethylbicyclo[2.2.1]heptan‐2‐one ( 5 )8 under standard coupling conditions (ethyl chloroformate and Et 3 N in CHCl 3 ) to give the corresponding amides ( 6 a and 6 b ) in 85 and 88 % isolated yields, respectively (Scheme ). Sodium borohydride reduction of 6 a and 6 b to provide the corresponding exo ‐alcohols 7 a and 7 b as a single diastereomer, which was treated with trifluoroacetic acid (TFA) in CH 2 Cl 2 to generate the desired organocatalysts 4 a and 4 b without incident.…”

Exploiting Imine Photochemistry for Masked N‐Centered Radical Reactivity

“…This work also represents ar are prior example of a1 -aminoNB in the literature;o fn ote,t he majority of prior 1-aminoNB preparations generate the bridgehead amine via aH ofmann or aC urtius rearrangement of terpene-based materials [43][44][45][46] or from downstream products of cyclopentadiene-acrylate Diels-Alder reactions [47][48][49][50] (only one radicalbased closure [51] existed before our work [18] ).…”

“…One example of an imine‐specific rearrangement is the photo‐racemization of dihydropyrazine (−)‐ 3 (see Figure A), facilitated by the non‐classical bond structure available to [2.2.1] bicyclic systems with open‐shell character adjacent to the bridgehead position. This work also represents a rare prior example of a 1‐aminoNB in the literature; of note, the majority of prior 1‐aminoNB preparations generate the bridgehead amine via a Hofmann or a Curtius rearrangement of terpene‐based materials or from downstream products of cyclopentadiene‐acrylate Diels–Alder reactions (only one radical‐based closure existed before our work).…”