32623-18-0Relevant academic research and scientific papers
Catalytic Asymmetric Radical Diamination of Alkenes
Wang, Fu-Li,Dong, Xiao-Yang,Lin, Jin-Shun,Zeng, Yang,Jiao, Guan-Yuan,Gu, Qiang-Shuai,Guo, Xian-Qi,Ma, Can-Liang,Liu, Xin-Yuan
supporting information, p. 979 - 990 (2017/12/26)
Catalytic asymmetric diamination of alkenes is a highly attractive method for creating chiral vicinal diamines, which are ubiquitous in biologically active molecules and versatile ligands as well as organocatalysts. We report the use of O-acylhydroxylamines as dialkylaminyl radical precursors to trigger asymmetric diamination of alkene under Cu(I)/chiral phosphoric acid dual catalysis. This reaction allows for direct alkylamine incorporation and features high enantioselectivity, a broad substrate scope, wide functional-group tolerance, and mild reaction conditions, providing convenient and practical access to a wide range of highly enantio-enriched β-alkylamine-containing pyrrolidines. We have also achieved asymmetric azidoamination of alkenes by using azidoiodinane as an azidyl radical precursor, offering a complementary method for preparing diverse chiral β-amino pyrrolidines. The application of the resultant α-tertiary pyrrolidine-derived diamine was showcased to significantly promote the enantioselectivity of an asymmetric Michael reaction. Chiral vicinal diamines are characteristic and essential motifs embedded in numerous biologically active molecules. In addition, they are also the core scaffolds for a diverse range of chiral ligands, organocatalysts, and auxiliaries widely used in organic synthesis. For their preparation, asymmetric diamination of readily available alkenes constitutes an expedient and important method for accessing enantio-enriched vicinal diamines. However, none of the known strategies are able to directly introduce a protection-free alkyl amine moiety, mainly because of its strong coordination capability, mostly leading to transition-metal catalyst poisoning and susceptibility to oxidation. As a consequence, both the step economy and amine scope are compromised, thus limiting broad applicability. Here, we report the asymmetric radical diamination of alkenes under Cu(I)/chiral phosphoric acid dual catalysis, enabling direct incorporation of alkyl amine groups. Liu and colleagues describe the asymmetric radical diamination of alkenes triggered by intermolecular addition of dialkylaminyl or azidyl radical to the alkene under Cu(I)/chiral phosphoric acid dual catalysis. This reaction enables direct incorporation of alkylamine moieties and provides convenient and practical access to a wide range of highly enantio-enriched β-alkylamine-containing pyrrolidines. Moreover, the resulting α-tertiary pyrrolidine-derived diamine proves to significantly promote the enantioselectivity of an asymmetric Michael reaction.
Nickel-catalyzed ring-opening cross-coupling of cyclic alkenyl ethers with arylboronic esters via carbon-oxygen bond cleavage
Ohtsuki, Akimichi,Sakurai, Shun,Tobisu, Mamoru,Chatani, Naoto
supporting information, p. 1277 - 1279 (2016/11/09)
We have developed a nickel-catalyzed cross-coupling reaction of cyclic alkenyl ethers with arylboronic esters that leads to the formation of unsaturated alcohols via ring-opening by the cleavage of a C(sp2)-O bond. The use of 1,3-dicyclohexylimidazol-2-ylidene as the ligand is essential to promote this cross-coupling process.
Cobalt-catalyzed oxidative cyclization of gem-disubstituted conjugated alkenols
Alves, Tania M.F.,Costa, Mateus O.,Bispo, Beatriz A.D.,Pedrosa, Fabiana L.,Ferreira, Marco A.B.
, p. 3334 - 3338 (2016/07/11)
Aryl gem-disubstituted conjugated alkenols underwent oxidative cyclization affording 2,5,5-trisubstituted tetrahydrofurans in reasonable yields and good diastereoselectivities using the reductive termination variation of the Mukaiyama aerobic oxidative reaction. Under oxidative termination, the same alkenols produced diols and ketonic by-products via the double hydration and beta-scission competing pathways. Furthermore, the differences in alkenol reactivity under the reductive and oxidative termination conditions were investigated.
Homohalocyclization: Electrophilic Bromine-Induced Cyclizations of Cyclopropanes
R?sner, Christian,Hennecke, Ulrich
supporting information, p. 3226 - 3229 (2015/07/15)
An efficient method for the halocyclization of cyclopropanes has been developed. The cyclopropanes undergo a 1,3-addition reaction to form homohalocyclization products compared to conventional alkene halocyclizations. The reaction can be induced by variou
Enantioselective bromoaminocyclization using amino-thiocarbamate catalysts
Zhou, Ling,Chen, Jie,Tan, Chong Kiat,Yeung, Ying-Yeung
supporting information; experimental part, p. 9164 - 9167 (2011/08/04)
A facile and efficient enantioselective bromoaminocyclization of unsaturated sulfonamides has been developed using an amino-thiocarbamate catalyst. A range of enantioenriched pyrrolidines were prepared with up to 99% yield and 99% ee. The corresponding lactams could be obtained through oxidation of the pyrrolidines.
Enantioselective Total Syntheses and Stereochemical Studies of All Four Stereoisomers of Yingzhaosu C
Xu, Xing-Xiang,Dong, Han-Qing
, p. 3039 - 3044 (2007/10/02)
The enantioselective total syntheses and the stereochemistry of all four stereoisomers of yingzhaosu C, an antimalarial peroxy-containing sesquiterpene isolated from yingzhao , are described.The key to the syntheses was th
Synthesis of aryl-substituted aldehydes and ketones via palladium-catalyzed coupling of aryl halides and non-allylic unsaturated alcohols
Larock,Leung,Stolz-Dunn
, p. 6629 - 6632 (2007/10/02)
The palladium-catalyzed coupling of aryl halides and non-allylic unsaturated alcohols affords excellent yields of aryl-substituted aldehydes and ketones.
