An alternative construction of A-B-D ring-system of erythrinan and homoerythrinan alkaloids by TiCl4-mediated tandem semipinacol/intramolecular Schmidt reaction of α-siloxyepoxyazide was addressed and the unusual epo...An alternative construction of A-B-D ring-system of erythrinan and homoerythrinan alkaloids by TiCl4-mediated tandem semipinacol/intramolecular Schmidt reaction of α-siloxyepoxyazide was addressed and the unusual epoxidation stereoselectivity was observed in preparation of the substrate once again.展开更多
Construction of the polyaryl quaternary unit through a ZnBr2 catalyzed tandem coupling/semipinacol rearrangement participated by allylic cations was reported for the first time.
Hydroxyphosphoric acids display the unique biological activities,and they have some attractive prospects as clinical drug moleculars.Herein,a new approach for the synthesis ofγ-oxo-phosphonates(the precursor of hydro...Hydroxyphosphoric acids display the unique biological activities,and they have some attractive prospects as clinical drug moleculars.Herein,a new approach for the synthesis ofγ-oxo-phosphonates(the precursor of hydroxyphosphoric acid)has been established through the semipinacol rearrangement tactic involved the photo-induced phosphorus radical process.Most important,this transformation is avoid of the external oxidants,and occurs very well under the sunlight irradiation,meanwhile theγ-oxo-phosphonate was easily derivatized to obtainγ-hydroxyphosphoric acid,thus highlights the synthesis value of this method.展开更多
The semipinacol rearrangement is one of the classic yet useful synthetic tools in organic synthesis.However,semipinacol rearrangements involving heteroatom-migration are rare.Reported herein is a boryl-migratory semip...The semipinacol rearrangement is one of the classic yet useful synthetic tools in organic synthesis.However,semipinacol rearrangements involving heteroatom-migration are rare.Reported herein is a boryl-migratory semipinacol rearrangement of α-hydroxyallylboronates and α-hydroxypropargylboronates triggered by diverse halogen-,oxygen-,sulfur-and seleniumcontaining electrophiles.The protocol leads to a mild and facile access to organoborons bearing valuable functionalities.The σ(C-B)hyperconjugation is believed to be the key factor that leads to the observed exclusive chemoselectivity and enhanced reactivity.Synthetic utilities of the formed products were demonstrated.展开更多
Low molecular weight poly（glycidyl methacrylate）s （PGMAs） were prepared by photopolymerization in ethyl acetate, with benzophenone （BP） as photoinitiator, and triethylamine （TEA） as hydrogen donor. The existen...Low molecular weight poly（glycidyl methacrylate）s （PGMAs） were prepared by photopolymerization in ethyl acetate, with benzophenone （BP） as photoinitiator, and triethylamine （TEA） as hydrogen donor. The existence of semipinacol dormant end groups in PGMA was confirmed by FT-IR and ^1H-NMR, and the content of the semipinacol dormant groups was determined quantitatively by ^1H-NMR measurement. The effects of various thctors, such as reaction time, BP concentration and monomer concentration on the synthesis of the polymers were investigated systematically. The molecular weights of the polymers were also investigated with GPC. It is shown that increasing BP concentration and decreasing irradiation time and monomer concentration led to a significant decrease of the molecular weights.展开更多
文摘An alternative construction of A-B-D ring-system of erythrinan and homoerythrinan alkaloids by TiCl4-mediated tandem semipinacol/intramolecular Schmidt reaction of α-siloxyepoxyazide was addressed and the unusual epoxidation stereoselectivity was observed in preparation of the substrate once again.
基金supported by the National Natural Science Foundation of China (Grant Nos. 20621091,20672048,and 20732002)the "111" program of Chinese Education Ministry
文摘Construction of the polyaryl quaternary unit through a ZnBr2 catalyzed tandem coupling/semipinacol rearrangement participated by allylic cations was reported for the first time.
基金the National Natural Science Foundation of China(No.21532001)International Joint Research Centre for Green Catalysis and Synthesis,Gansu provincial Sci.&Tech.Department(No.2016B01017)for financial support。
文摘Hydroxyphosphoric acids display the unique biological activities,and they have some attractive prospects as clinical drug moleculars.Herein,a new approach for the synthesis ofγ-oxo-phosphonates(the precursor of hydroxyphosphoric acid)has been established through the semipinacol rearrangement tactic involved the photo-induced phosphorus radical process.Most important,this transformation is avoid of the external oxidants,and occurs very well under the sunlight irradiation,meanwhile theγ-oxo-phosphonate was easily derivatized to obtainγ-hydroxyphosphoric acid,thus highlights the synthesis value of this method.
基金supported by the National Natural Science Foundation of China(22022114,21971261)the Key Project of Chinese National Programs for Fundamental Research and Development(2016YFA0602900)+3 种基金the Guang-dong Basic and Applied Basic Research Foundation(2020A1515010624)the Fundamental Research Funds for the Central Universities(20ykzd12)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y093)the China Postdoctoral Science Foundation(2021M69360)。
文摘The semipinacol rearrangement is one of the classic yet useful synthetic tools in organic synthesis.However,semipinacol rearrangements involving heteroatom-migration are rare.Reported herein is a boryl-migratory semipinacol rearrangement of α-hydroxyallylboronates and α-hydroxypropargylboronates triggered by diverse halogen-,oxygen-,sulfur-and seleniumcontaining electrophiles.The protocol leads to a mild and facile access to organoborons bearing valuable functionalities.The σ(C-B)hyperconjugation is believed to be the key factor that leads to the observed exclusive chemoselectivity and enhanced reactivity.Synthetic utilities of the formed products were demonstrated.
基金The authors are grateful to the National Natural Science Foundation of China (No. 50433040) for the financial support.
文摘Low molecular weight poly（glycidyl methacrylate）s （PGMAs） were prepared by photopolymerization in ethyl acetate, with benzophenone （BP） as photoinitiator, and triethylamine （TEA） as hydrogen donor. The existence of semipinacol dormant end groups in PGMA was confirmed by FT-IR and ^1H-NMR, and the content of the semipinacol dormant groups was determined quantitatively by ^1H-NMR measurement. The effects of various thctors, such as reaction time, BP concentration and monomer concentration on the synthesis of the polymers were investigated systematically. The molecular weights of the polymers were also investigated with GPC. It is shown that increasing BP concentration and decreasing irradiation time and monomer concentration led to a significant decrease of the molecular weights.
