The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIVfunctionalization is synthetically attractive but challenging due to the competitive reaction...The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIVfunctionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective SIV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center(N-R). The origin of the high SIV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes.展开更多
Stereoselective approach for preparation ofα-difluoromethylα-propargylamines has been developed.1,2-Addition of lithium acetylides to diverse chiral difluoromethylated（S）-N-tert-butanesulfinyl ketimines by using T...Stereoselective approach for preparation ofα-difluoromethylα-propargylamines has been developed.1,2-Addition of lithium acetylides to diverse chiral difluoromethylated（S）-N-tert-butanesulfinyl ketimines by using Ti（O^iPr）_4 as catalyst and THF as solvent afforded N-tert-butanesulfinamides in good to excellent yields（51-93%） and good diastereoselectivities（dr.85：15 to 93：7）.The N-tert -butanesulfinyl group can be readily cleaved under mild acidic condition（4 mol/L HCl in dioxane） to provide the correspondingα-difiuoromethylα-propargylamine in excellent yields（90-95%）.展开更多
We report the polymerization of phenyl isocyanides with the chiral palladium（II） initiating system. The resulting polymers with optically active properties were obtained by polymerization of the racemic isocyanide m...We report the polymerization of phenyl isocyanides with the chiral palladium（II） initiating system. The resulting polymers with optically active properties were obtained by polymerization of the racemic isocyanide monomer （rac-1）, and enantiomerically unbalanced polymerization of the monomer was found, providing substantial evidence for the enantiomer-selective polymerization of rac- 1 mediated through chiral catalyst. A comparison between the enantiomerically pure monomers, 4-isocyanobenzoyl-L-alanine decyl ester （1 s） and 4-isocyanobenzoyl-D-alanine decyl ester （1 r）, revealed a drastic discrepancy in the reactivity ratio of their homopolymerizations. It turned out that the monomer reactivity ratio of ls was higher than that of lr with chiral ligands. The results clearly demonstrated the inclination for incorporation of the ls enantiomer during the polymerization process and thus resulted in the enantiomer-selective polymerization in this system. The effects of the catalyst chirality on the optically active properties of polymerization were investigated, and it was concluded that the formation of higher-ordered conformation with a handed helicity might be attributed to the chiral induction of chiral palladium（II） catalyst. Moreover, the polymers obtained through the enantiomer-selective polymerization of the enantiomerically pure monomer were with a significant improvement of the optical activity if the chirality of the monomer and the catalyst matched with each other.展开更多
Sulfonimidoyl fluorides,the aza-bioisostere of sulfonyl fluorides,are emerging as a promising linkage agent in the sulfur(VI)fluoride exchange reaction(SuFEx).However,conventional synthetic approaches typically requir...Sulfonimidoyl fluorides,the aza-bioisostere of sulfonyl fluorides,are emerging as a promising linkage agent in the sulfur(VI)fluoride exchange reaction(SuFEx).However,conventional synthetic approaches typically require the use of either unstable sulfonimidoyl chlorides,toxic and corrosive sulfur fluorides,or expensive electrophilic fluorinating agents.Herein,we report an electrochemistry-enabled oxidative nucleophilic fluorination of readily available and bench-stable sulfinamides using a commercially available and easy-to-handle triethylamine trihydrofluoride.With other nucleophilic agents,this electrochemical approach also serves as a general approach to diverse sulfonimidoyl derivatives,including sulfonimidoyl azides and acetates.展开更多
基金supported by the National Natural Science Foundation of China(22001065)the Science and Technology Foundation of Hunan Province(2021JJ30090)+3 种基金Guangdong Provincial Key Laboratory of Catalysis(2020B121201002)Shenzhen Science and Technology Program(KQTD20210811090112004)supported by Center for Computational Science and Engineering at SUSTechthe CHEM high-performance supercomputer cluster(CHEM-HPC)located at the Department of Chemistry,SUSTech。
文摘The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIVfunctionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective SIV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center(N-R). The origin of the high SIV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes.
基金The Shanghai Pujiang Program(No09PJ1400800)the Fundamental Research Funds for the Central Universities and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘Stereoselective approach for preparation ofα-difluoromethylα-propargylamines has been developed.1,2-Addition of lithium acetylides to diverse chiral difluoromethylated（S）-N-tert-butanesulfinyl ketimines by using Ti（O^iPr）_4 as catalyst and THF as solvent afforded N-tert-butanesulfinamides in good to excellent yields（51-93%） and good diastereoselectivities（dr.85：15 to 93：7）.The N-tert -butanesulfinyl group can be readily cleaved under mild acidic condition（4 mol/L HCl in dioxane） to provide the correspondingα-difiuoromethylα-propargylamine in excellent yields（90-95%）.
基金financially supported by the National Natural Science Foundation of China (Nos. 51673057, 21622402, and 21574036)N. Liu thanks Anhui Provincial Natural Science Foundation (No. 1608085MB41)
文摘We report the polymerization of phenyl isocyanides with the chiral palladium（II） initiating system. The resulting polymers with optically active properties were obtained by polymerization of the racemic isocyanide monomer （rac-1）, and enantiomerically unbalanced polymerization of the monomer was found, providing substantial evidence for the enantiomer-selective polymerization of rac- 1 mediated through chiral catalyst. A comparison between the enantiomerically pure monomers, 4-isocyanobenzoyl-L-alanine decyl ester （1 s） and 4-isocyanobenzoyl-D-alanine decyl ester （1 r）, revealed a drastic discrepancy in the reactivity ratio of their homopolymerizations. It turned out that the monomer reactivity ratio of ls was higher than that of lr with chiral ligands. The results clearly demonstrated the inclination for incorporation of the ls enantiomer during the polymerization process and thus resulted in the enantiomer-selective polymerization in this system. The effects of the catalyst chirality on the optically active properties of polymerization were investigated, and it was concluded that the formation of higher-ordered conformation with a handed helicity might be attributed to the chiral induction of chiral palladium（II） catalyst. Moreover, the polymers obtained through the enantiomer-selective polymerization of the enantiomerically pure monomer were with a significant improvement of the optical activity if the chirality of the monomer and the catalyst matched with each other.
基金the National Natural Science Foundation of China(grant no.22171046)the Hundred-Talent Project of Fujian(grant no.50021113)is gratefully acknowledged.
文摘Sulfonimidoyl fluorides,the aza-bioisostere of sulfonyl fluorides,are emerging as a promising linkage agent in the sulfur(VI)fluoride exchange reaction(SuFEx).However,conventional synthetic approaches typically require the use of either unstable sulfonimidoyl chlorides,toxic and corrosive sulfur fluorides,or expensive electrophilic fluorinating agents.Herein,we report an electrochemistry-enabled oxidative nucleophilic fluorination of readily available and bench-stable sulfinamides using a commercially available and easy-to-handle triethylamine trihydrofluoride.With other nucleophilic agents,this electrochemical approach also serves as a general approach to diverse sulfonimidoyl derivatives,including sulfonimidoyl azides and acetates.
