In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Chemoselective calcium-catalyzed direct amidation of carboxylic esters, published in 2015, which mentions a compound: 37443-42-8, mainly applied to amide green preparation chemoselective; carboxylic ester primary amine calcium catalyst amide bond formation, SDS of cas: 37443-42-8.
Unactivated carboxylic esters and primary amines undergo calcium-catalyzed direct amide bond formation to afford amides I [R1 = n-Pr, Ph, 4-hydroxybutyl, etc.; R2 = 2-thienyl, Ph, Bn, etc.] in excellent yields under homogeneous conditions in toluene. This green and mild reaction proceeds chemoselectively with esters, whereas related carboxylic acids and amides remain unreactive.
In some applications, this compound(37443-42-8)SDS of cas: 37443-42-8 is unique.If you want to know more details about this compound, you can contact with the author or consult more relevant literature.
Reference:
Benzisoxazole – Wikipedia,
Benzisoxazole – an overview | ScienceDirect Topics