615-77-0Relevant articles and documents
Copper-Catalyzed Regioselective Direct C–H Thiolation and Thiocyanation of Uracils
Noikham, Medena,Yotphan, Sirilata
supporting information, p. 2759 - 2766 (2019/04/08)
A novel copper-catalyzed direct C–H thiolation and thiocyanation of uracils using disulfides and thiocyanate salts respectively as coupling partners are described. These reactions enable the C–H bond cleavage and C–S bond formation to proceed efficiently under relatively mild conditions, providing useful methods for a preparation of a series of thio-substituted at the C5 position of uracil derivatives. These protocols exhibit several merits including simple experimental procedures, readily accessible substrates and reagents, broad scopes, high yields, and excellent regioselectivity. Preliminary mechanistic studies revealed that a radical pathway is likely to be involved.
Oxidative cleavage of a cyclobutane pyrimidine dimer by photochemically generated nitrate radicals (no(3)*).
Krueger,Wille
, p. 1455 - 1458 (2007/10/03)
[reaction: see text] Photochemically generated nitrate radicals (NO(3)(*)) cleave the stereoisomeric N,N-dimethyl-substituted uracil cyclobutane dimers 1a-d into the monomeric uracil derivative 2 as the major reaction pathway. A preferred splitting of the syn dimers 1a,b was observed. The reaction is expected to proceed through initial one-electron oxidation with formation of an intermediate cyclobutane radical cation 11. In addition to cycloreversion, competing reaction steps of 11, which lead to the observed byproducts, are suggested.
SYNTHESIS OF REGIOSPECIFICALLY SUBSTITUTED PYRIMIDYL DERIVATIVES AND THEIR INCORPORATION INTO PENEMS
Capraro, Hans-Georg,Lang, Marc,Schneider, Peter
, p. 643 - 652 (2007/10/02)
Syntheses of regiospecifically substituted pyrimidines are described.Depending on the reaction conditions, N1- or N3-substituted pyrimidines are obtained.It has been shown that substitution on uracil under Mitsunobu conditions yields N1-substituted products.Incorporation of these derivatives into the penem nucleus gives penem antibiotics with extremely long half-lives.
