Rajamanickam, Suresh published the artcileIntermolecular CDC amination of remote and proximal unactivated Csp3-H bonds through intrinsic substrate reactivity – expanding towards a traceless directing group, Application In Synthesis of 2251-79-8, the publication is Chemical Science (2021), 12(46), 15318-15328, database is CAplus and MEDLINE.
An intermol. radical based distal selectivity in appended alkyl chains, e.g., I has been developed. The selectivity is maximum when the distal carbon is γ to the appended group and decreases by moving from γ → δ → ε positions. In -COO- linked alkyl chains, the same distal γ-selectivity is observed irresp. of its origin, either from the alkyl carboxy acid or alkyl alc. The appended groups include esters, N-H protected amines, phthaloyl, sulfone, sulfinimide, nitrile, phosphite, phosphate and borate esters. In borate esters, boron serves as a traceless directing group, which is hitherto unprecedented for any remote Csp3-H functionalization. The selectivity order follows the trend: 3° benzylic > 2° benzylic > 3° tertiary > α to keto > distal methylene (γ > δ > ε). Computations predicted the radical stability (thermodn. factors) and the kinetic barriers as the factors responsible for such trends. Remarkably, this strategy eludes any designer catalysts, and the selectivity is due to the intrinsic substrate reactivity.
Chemical Science published new progress about 2251-79-8. 2251-79-8 belongs to isoxazole, auxiliary class Trifluoromethyl,Fluoride,Benzene, name is 5-(4-(Trifluoromethyl)phenyl)-1H-tetrazole, and the molecular formula is C8H5F3N4, Application In Synthesis of 2251-79-8.
Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem