Methyl 3-trimethylsilylpropargyl carbonate reacted with dinucleophiles under the catalysis of palladium(0) complex to give the corresponding desilylated annulation products.
Phosphine-catalyzed[5+1]annulation reaction of Morita-Baylis-Hillman(MBH)carbonates with 1,3-dicarbonyl compounds has been developed,producing biologically interesting spirocyclohexene derivatives in high yields with ...Phosphine-catalyzed[5+1]annulation reaction of Morita-Baylis-Hillman(MBH)carbonates with 1,3-dicarbonyl compounds has been developed,producing biologically interesting spirocyclohexene derivatives in high yields with moderate to excellent diastereoselectivities.The annulation was achieved through sequential 1,6-conjugate addition/nucleophilic substution reaction of phosphine ylides with dinucleophiles.展开更多
Despite the widespread use of allyl bromides in organic synthesis,the asymmetric transformation of allyl bromides has been less developed.To date,the asymmetric transformation of allyl bromides has been limited to sin...Despite the widespread use of allyl bromides in organic synthesis,the asymmetric transformation of allyl bromides has been less developed.To date,the asymmetric transformation of allyl bromides has been limited to single-site functionalization,and the development of dual-site asymmetric functionalization remains unexplored.In this work,the unprecedented asymmetric dual-site functionalization of allyl bromides has been realized through an efficient organocatalytic system,overcoming the persistent limitation of single-site transformations.Employing dinucleophiles including 3-aminobenzofurans,2-aminoindoles,and cyclohexane-1,3-diones,this methodology affords benzofuro[3,2-b]pyridines andα-carbolines in good yields with excellent stereoselectivity.The transformation proceeds via a chemoselective S_(N)2′pathway mediated by a chiral pyrrolidinyl sulfonamide catalyst,which generates ammonium salts in situ to achieve stereocontrol.The protocol was successfully extended to enantioenriched privileged pyran frameworks,and was applied to diverse downstream transformations.Gram-scale synthesis maintained high enantioselectivity,confirming practical utility.This approach effectively addresses key challenges in efficient construction of complex fused-ring heterocycles,substantially expanding the synthetic applications of allyl bromides.展开更多
The reaction of 3-（1-hydropolyfluoroalkenyl）-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was investigated. 7-Fluoroalkyl-2,3-dihydro- 1,4-diazepine[ 1,2-d]quinazolin- 11-ones 2, 2-fluoroalkylisoxazolo[3,2-b]...The reaction of 3-（1-hydropolyfluoroalkenyl）-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was investigated. 7-Fluoroalkyl-2,3-dihydro- 1,4-diazepine[ 1,2-d]quinazolin- 11-ones 2, 2-fluoroalkylisoxazolo[3,2-b]quinazolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane, hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.展开更多
文摘Methyl 3-trimethylsilylpropargyl carbonate reacted with dinucleophiles under the catalysis of palladium(0) complex to give the corresponding desilylated annulation products.
文摘Phosphine-catalyzed[5+1]annulation reaction of Morita-Baylis-Hillman(MBH)carbonates with 1,3-dicarbonyl compounds has been developed,producing biologically interesting spirocyclohexene derivatives in high yields with moderate to excellent diastereoselectivities.The annulation was achieved through sequential 1,6-conjugate addition/nucleophilic substution reaction of phosphine ylides with dinucleophiles.
基金Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)Taishan Scholar Program of Shandong Province(No.tsqn202103152)National Natural Science Foundation of China(Nos.22201270,22471250)for financial support.
文摘Despite the widespread use of allyl bromides in organic synthesis,the asymmetric transformation of allyl bromides has been less developed.To date,the asymmetric transformation of allyl bromides has been limited to single-site functionalization,and the development of dual-site asymmetric functionalization remains unexplored.In this work,the unprecedented asymmetric dual-site functionalization of allyl bromides has been realized through an efficient organocatalytic system,overcoming the persistent limitation of single-site transformations.Employing dinucleophiles including 3-aminobenzofurans,2-aminoindoles,and cyclohexane-1,3-diones,this methodology affords benzofuro[3,2-b]pyridines andα-carbolines in good yields with excellent stereoselectivity.The transformation proceeds via a chemoselective S_(N)2′pathway mediated by a chiral pyrrolidinyl sulfonamide catalyst,which generates ammonium salts in situ to achieve stereocontrol.The protocol was successfully extended to enantioenriched privileged pyran frameworks,and was applied to diverse downstream transformations.Gram-scale synthesis maintained high enantioselectivity,confirming practical utility.This approach effectively addresses key challenges in efficient construction of complex fused-ring heterocycles,substantially expanding the synthetic applications of allyl bromides.
基金Project supported by the National Natural Science Foundation of China （No. 20172065）.
文摘The reaction of 3-（1-hydropolyfluoroalkenyl）-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was investigated. 7-Fluoroalkyl-2,3-dihydro- 1,4-diazepine[ 1,2-d]quinazolin- 11-ones 2, 2-fluoroalkylisoxazolo[3,2-b]quinazolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane, hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.
