In 2022,Xu, Wen-Ke; Guo, Jia-Ming; Liu, Chang-Hong; Sun, Jian-Ting; Lv, Min; Wei, Bang-Guo published an article in Organic & Biomolecular Chemistry. The title of the article was 《AgNTf2 catalyzed cycloaddition of N-acyliminium ions with alkynes for the synthesis of the 3,4-dihydro-1,3-oxazin-2-one skeleton》.Formula: C5H11NO2 The author mentioned the following in the article:
A catalyzed process for the synthesis of 4,6-substituted 3,4-dihydro-1,3-oxazin-2-one I [R = cyclopropyl, Ph, thiophen-2-yl, etc.; R1 = Ph, 4-ethynylphenyl, thiophen-3-yl, etc.] skeleton has been developed through cycloaddition of in situ generated acyliminium intermediates with alkynes R1CCH. A range of chain N,O-acetals (CH3)3COC(O)NHCH(OCH3)(R) and terminal alkynes was amenable for this mild transformation. As a result, a series of desired cycloaddition products I were obtained in moderate to good yields. The results came from multiple reactions, including the reaction of tert-Butyl carbamate(cas: 4248-19-5Formula: C5H11NO2)
tert-Butyl carbamate(cas: 4248-19-5) belongs to anime. In organic chemistry, amines are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (NH3), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines).Formula: C5H11NO2
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics