Convenient Synthesis of 4-Methylene-2-oxazolidinones and 4-Methylenetetrahydro-1,3-oxazin-2-ones via Transition-Metal Catalyzed Intramolecular Addition of Nitrogen Atom to Acetylenic Triple Bond
作者:Yoshinao Tamaru、Masanari Kimura、Shuji Tanaka、Sigeru Kure、Zen-ichi Yoshida
DOI:10.1246/bcsj.67.2838
日期:1994.10
2-Propynyl tosylcarbamates 1 undergo cyclization smoothly by the catalysis of CuCl/Et3N or AgNCO/Et3N to furnish 4-methylene-2-oxazolidinones 2 in good yields. The similar cyclization of the N-acyl derivatives of 1 (PhCO, MeCO, EtOCO, etc.) is catalyzed effectively by AgNCO/t-BuOK. These reactions accommodate a variety of substituents at C1 and C3 of 2-propyn-1-ol and provide (Z)-2 as single stereoisomers. The scope of the cyclization of 3-butynyl carbamates is rather limited, and in general only N-tosyl derivatives of terminally unsubstituted 3-butyn-1-ols undergo cyclization to give 4-methylenetetrahydro-1,3-oxazin-2-ones in synthetically useful yields by the catalysis of AgNCO/Et3N or AgNCO/t-BuOK.
Palladium-Catalyzed Intramolecular Hydroamination of Propargylic Carbamates and Carbamothioates
作者:Santosh Kumar Alamsetti、Andreas K. Å. Persson、Jan-E. Bäckvall
DOI:10.1021/ol5002279
日期:2014.3.7
An efficient and simple methodology was developed for the synthesis of oxazolidinones, oxazolidinthiones, imidazolidinthiones, and imidazolidinones from the corresponding propargylic starting materials using Pd(OAc)2 and n-Bu4NOAc as catalysts in DCE at room temperature.
开发了一种有效且简单的方法,用于在室温下在DCE中使用Pd(OAc)2和n- Bu 4 NOAc作为催化剂,从相应的炔丙基原料合成恶唑烷酮,恶唑烷硫酮,咪唑烷硫酮和咪唑烷酮。
5-Exo-dig aminocylization/hydroxyfluorination of propargylic carbamates
作者:Antonio Arcadi、Marco Chiarini、Luana Del Vecchio、Fabio Marinelli
DOI:10.1016/j.jfluchem.2018.04.002
日期:2018.7
The reaction was effectively promoted by NaHCO3 and/or silver catalysis. The peculiar behavior of propargylic carbamates bearing a chiral steroidal moiety is described. Extensions and limitations of the procedure with respect to urea derivatives, homopropargyl compounds, internal alkynes and one-pottransformations of propargylic alcohols with isocyanates are reported.
O-Propargyl carbamates 1 undergo an intramolecular nucleophilic addition to acetylenic bond at the nitrogen atom to furnish 4-methylene-2-oxazolidinones 2 in good yields in the presence (Cu+ for R1 = p-toluenesulfonyl, Ag+ for R1 = acyl) or absence (for R1 = alkyl and aryl) of a transition metal catalyst.
O-丙炔基氨基甲酸酯1在氮原子上的炔键上进行分子内亲核加成,从而以高收率提供4-亚甲基-2-恶唑烷酮2(Cu + R 1 =对甲苯磺酰基,Ag + R 1 =酰基)或不存在(对于R 1 =烷基和芳基)的过渡金属催化剂。
Palladium-Catalyzed Synthesis of Stereodefined 4-Arylidene-3 Tosyloxazolidin-2-ones from 2-Propynyl Tosylcarbamates and Unsaturated Halides (or Triflate)
2-propynyl tosylcarbamates undergo cyclisation-coupling reactions with aryl iodides (and one alkenyl triflate) in the presence of base and of catalytic amounts of a palladium(0)-phosphine complex to form (E)-4-arylidene or 4-alkylidene-3-tosyloxazolidin-2-ones in a regio- and stereoselective manner.