A general preparation of polyfunctional hydroxylamine benzoates from the corresponding secondary amines is reported. This convenient synthesis allows the setup of a late-stage functionalization of various secondary amines, including pharmaceuticals and peptidic derivatives. Thus, a cross-coupling of hydroxylamine benzoates with various alkyl-, aryl-, and heteroaryl-zinc chlorides in the presence of
A highly chemoselective conjugateaddition of alcohols in the presence of amines is described. The cooperative nature of the catalyst enabled chemoselective activation of alcohols over amines, allowing the conjugateaddition to soft Lewis basic α,β‐unsaturated nitriles. Divergent transformation of the nitrile functionality highlights the utility of the present catalysis.
An efficient biomaterial supported bifunctional organocatalyst (ES-SO3− C5H5NH+) for the synthesis of β-amino carbonyls
作者:Sanny Verma、Suman L. Jain、Bir Sain
DOI:10.1039/c0ob00965b
日期:——
A biomaterial supported organocatalyst, readily synthesized by the reaction of chemically modified sulfonic group containing expanded corn starch with pyridine exhibited excellent catalytic activity for the synthesis of β-amino carbonyls in excellent yields via aza-Michael addition of amines to electron deficient alkenes. A remarkable enhancement in the reaction rates was observed with the prepared bifunctional organocatalyst in comparison to the either starch grafted sulfonic acid or the corresponding homogeneous pyridinium p-toluenesulfonate.
Poly(hydroxamic acid) functionalized copper catalyzed C–N bond formation reactions
作者:Md. Shaharul Islam、Bablu Hira Mandal、Tapan Kumar Biswas、Md. Lutfor Rahman、S. S. Rashid、Suat-Hian Tan、Shaheen M. Sarkar
DOI:10.1039/c6ra08155j
日期:——
Highly active poly(hydroxamic acid) functionalized copper catalysts were synthesized by the surface modification of khaya cellulose through graft copolymerization and subsequent hydroximation processes. The prepared catalysts were well characterized by FTIR, FESEM, HRTEM, ICP-AES, UV-vis and XPS analyses. The supported catalysts effectively promoted C–N bond formation reactions and provided excellent