Access to Enantioenriched 1,<i>n</i>-Diamines via Ni-Catalyzed Hydroamination of Unactivated Alkenes with Weakly Coordinating Groups
作者:Peng-Fei Yang、Jian-Xing Liang、Han-Tong Zhao、Wei Shu
DOI:10.1021/acscatal.2c02892
日期:2022.8.5
chiral α-branched aliphatic amine motifs are important substructures in bioactive compounds and related molecules and serve as privileged chiral ligands in both organo- and transition-metal-catalysis. However, direct access to such structural motifs remains a formidable challenge. Herein, a straightforward method to access 1,n-diamines (n = 2, 3, 4) containing a chiral α-branched aliphatic amine is achieved
Ligand-Controlled NiH-Catalyzed Regiodivergent and Enantioselective Hydroamination of Alkenyl Amides
作者:Leipeng Xie、Jimin Liang、Haohao Bai、Xuanyu Liu、Xiao Meng、Yuan-Qing Xu、Zhong-Yan Cao、Chao Wang
DOI:10.1021/acscatal.3c01845
日期:2023.8.4
commercially available bidentate nitrogen-containing ligands, which enables delivery of 1,1-, 1,2-, and 1,3-diamines with good-to-excellent regioselectivity starting from the same substrates. A broad range of O-benzoylhydroxylamine electrophiles with different functional groups can be installed via Ni migration or nonmigration. Moreover, these predicable and positionally selective protocols provide a
Curran, Dennis P.; Gothe, Scott A.; Choi, Sung-Mo, Heterocycles, 1993, vol. 35, # 2, p. 1371 - 1395
作者:Curran, Dennis P.、Gothe, Scott A.、Choi, Sung-Mo
DOI:——
日期:——
Organoselenium- and proton-mediated cyclization reactions of allylic amides and thioamides. Syntheses of 2-oxazolines and 2-thiazolines
作者:Lars Engman
DOI:10.1021/jo00010a045
日期:1991.5
A variety of allylic amides and thioamides were treated with phenylselenenyl bromide in chloroform to give, via 5-exo cyclization, 2-oxazolines and 2-thiazolines, respectively, carrying a (phenylselenenyl)methyl substituent in the 5-position. In some cases (N-crotyl- and N-cinnamylamides/thioamides), dihydro-1,3-oxazines/-thiazines were formed via 6-endo cyclization. The phenylselenenyl group of the cyclofunctionalization products was slowly eliminated by treatment with m-chloroperbenzoic acid to introduce unsaturation in the resulting oxazoline/thiazoline. Reductive removal of the phenylselenenyl group was effected by treatment with triphenyltin hydride. This reaction was sometimes accompanied by a rearrangement of the heterocyclic ring. Proton-induced cyclizations of allylic thioamides to give 2-thiazolines was slowly but efficiently effected in boiling toluene containing a catalytic amount of p-toluenesulfonic acid.
We report the synthesis of N-benzyl-N-[(E)-buta-1,3-dienyl]propanamide (6) and its corresponding O-silyl-subitituted ketene N,O-acetal 7 and their Diels-Alder reaction. Propanamide G reacted smoothly, whereas the yield obtained from 7 was low, probably due to polymerization of the dienophile induced by electron transfer. The ketene N,O-acetals 27a-g were synthesized starting from the corresponding benzamides 25a-e (Scheme 9). The ketene N,O-acetals 27a-g showed increased stabilities and underwent amino-Claisen rearrangements under thermal conditions. Using catalysts, interesting side reactions leading either to the annulated systems, rac-35-37 or to a beta -lactam rac-34 were observed.