78698-19-8Relevant articles and documents
Stereocontrolled aziridination of imines via a sulfonium ylide route and a mechanistic study
Yang, Xiao-Fang,Zhang, Ming-Jie,Hou, Xue-Long,Dai, Li-Xin
, p. 8097 - 8103 (2002)
The reaction of N-diphenylphosphinoyl imines 1 with [3- (trimethylsilyl)allyl]dimethylsulfonium bromide (5) in the presence of NaH at room temperature predominantly gave trans-vinylaziridines 4. On the other hand, cis-vinylaziridines 4 were the main products when the preformed ylide prepared from the reaction of [3-(trimethylsilyl)allyl]diphenylsulfonium perchlorate (6) was reacted with the same imines 1 at low temperature. trans-Aziridines were also obtained when imines 1 and sulfinimines 9 were reacted with N,N-dimethylacetamide-2-dimethylsulfonium bromide (7) in the presence of a base, respectively. A mechanistic study showed that the stereochemistry of these reactions was controlled by the reactivity of the imines and ylides. A higher reactivity of imines and ylides favors the formation of cis-aziridines, whereas a lower reactivity leads to trans-products.
Cu(I)/chiral bisoxazoline-catalyzed enantioselective sommelet-hauser rearrangement of sulfonium ylides
Wang, Jianbo,Li, Shu-Sen
supporting information, p. 12343 - 12358 (2020/11/10)
Catalytic asymmetric thia-Sommelet-Hauser rearrangement of sulfonium ylides remains a great challenge due to its multistep reaction mechanism involving metal carbene formation, proton transfer, and [2,3]-sigmatropic rearrangement. In particular, the key problem of such reactions is the differentiation of the enantiotopic lone pair electrons of sulfur, which generates the sulfonium ylide intermediate bearing chirality on the sulfur atom. With a modified chiral bisoxazoline ligand, we developed a Cu(I)- catalyzed asymmetric thia-Sommelet-Hauser rearrangement with good to excellent enantioselectivities. Mechanistic studies provide insights into the details of the reaction mechanism.
Direct catalytic formation of primary and tertiary amides from non-activated carboxylic acids, employing carbamates as amine source
Tinnis, Fredrik,Lundberg, Helena,Adolfsson, Hans
supporting information, p. 2531 - 2536 (2012/11/06)
The operationally simple titanium(IV)- or zirconium(IV)-catalyzed direct amidation of non-activated carboxylic acids with ammonium carbamates generates primary, and tertiary N,N-dimethyl-substituted amides in good to excellent yields. Copyright