Asymmetric vinylogous C–X bond formation is rarely achieved due to competitiveα-functionalization and the oxidative nature of electrophilic X+reagents.This process usually results in the decomposition of the low-val...Asymmetric vinylogous C–X bond formation is rarely achieved due to competitiveα-functionalization and the oxidative nature of electrophilic X+reagents.This process usually results in the decomposition of the low-valent chiral transition metal catalyst which obstructs catalytic efficiency.Herein,by means of copper(I)catalysis,an asymmetric vinylogous selenenylation of(E)-β,γ-unsaturated pyrazole amides is accomplished in high enantioselectivity.The substrate scope is demonstrated to be broad for both(E)-β,γ-unsaturated pyrazole amides and selenosulfonates.Dynamic deuteration and background reaction illustrate that the chiral copper(I)-SL-J008-1 complex plays a key role in both the efficient enolization of(E)-β,γ-unsaturated pyrazole amides and the achievement ofγ-selectivity.Subsequent control experiments reveal allylcopper(I)species as the operating nucleophiles in the enantioselective vinylogous selenenylation.Finally,the synthetic utility of the present methodology has been demonstrated by versatile transformations of the product.展开更多
Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals,photocatalysts,strong bases,or/and malodorous thiols/selenols,with various mechanisms proposed.This study ...Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals,photocatalysts,strong bases,or/and malodorous thiols/selenols,with various mechanisms proposed.This study aims to leverage a new application of neutral ChB to address these challenges and enable a very simple photoinduced cross-electrophile C—S/Se coupling using readily available chalcogen electrophiles.Mechanistic investigations have revealed the important role of neutral ChB in facilitating single electron transfer processes,thereby enabling the generation of thiolates/selenolates from stable chalcogen electrophiles andα-aminoalkyl radicals,which possess the capability to abstract halogen atoms from aryl iodides.Moreover,the study provided support for the radical nucleophilic substitution mechanism.展开更多
基金the National Key R&D Program of China(grant no.2024YFA1210700)the National Natural Science Foundation of China(grant no.22271302)+1 种基金the Science and Technology Commission of Shanghai Municipality(grant no.LJ2023103)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB0590000).
文摘Asymmetric vinylogous C–X bond formation is rarely achieved due to competitiveα-functionalization and the oxidative nature of electrophilic X+reagents.This process usually results in the decomposition of the low-valent chiral transition metal catalyst which obstructs catalytic efficiency.Herein,by means of copper(I)catalysis,an asymmetric vinylogous selenenylation of(E)-β,γ-unsaturated pyrazole amides is accomplished in high enantioselectivity.The substrate scope is demonstrated to be broad for both(E)-β,γ-unsaturated pyrazole amides and selenosulfonates.Dynamic deuteration and background reaction illustrate that the chiral copper(I)-SL-J008-1 complex plays a key role in both the efficient enolization of(E)-β,γ-unsaturated pyrazole amides and the achievement ofγ-selectivity.Subsequent control experiments reveal allylcopper(I)species as the operating nucleophiles in the enantioselective vinylogous selenenylation.Finally,the synthetic utility of the present methodology has been demonstrated by versatile transformations of the product.
基金financial support from the National Natural Science Foundation of China(Nos.22173103,52063008)the Academic Talent Plan of Guizhou Normal University(No.Qian Shi Xin Miao[2021]27)the Fundamental Research Funds for the Central Universities and Beijing National Laboratory for Molecular Sciences(BNLMS2023014).
文摘Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals,photocatalysts,strong bases,or/and malodorous thiols/selenols,with various mechanisms proposed.This study aims to leverage a new application of neutral ChB to address these challenges and enable a very simple photoinduced cross-electrophile C—S/Se coupling using readily available chalcogen electrophiles.Mechanistic investigations have revealed the important role of neutral ChB in facilitating single electron transfer processes,thereby enabling the generation of thiolates/selenolates from stable chalcogen electrophiles andα-aminoalkyl radicals,which possess the capability to abstract halogen atoms from aryl iodides.Moreover,the study provided support for the radical nucleophilic substitution mechanism.
