The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Sukbok Chang - One of the best experts on this subject based on the ideXlab platform.
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catalytic access to bridged sila n heterocycles from Piperidines via cascade sp3 and sp2 c si bond formation
Journal of the American Chemical Society, 2018Co-Authors: Jianbo Zhang, Sehoon Park, Sukbok ChangAbstract:Described herein is the development of an unprecedented route to bridged sila-N-heterocycles via B(C6F5)3-catalyzed cascade silylation of N-aryl Piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) β-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp2 C–H silylation.
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Catalytic Access to Bridged Sila‑N‑heterocycles from Piperidines via Cascade sp3 and sp2 C–Si Bond Formation
2018Co-Authors: Jianbo Zhang, Sehoon Park, Sukbok ChangAbstract:Described herein is the development of an unprecedented route to bridged sila-N-heterocycles via B(C6F5)3-catalyzed cascade silylation of N-aryl Piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) β-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp2 C–H silylation
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Catalytic Access to Bridged Sila- N-heterocycles from Piperidines via Cascade sp3 and sp2 C-Si Bond Formation
AMER CHEMICAL SOC, 2018Co-Authors: Jianbo Zhang, Sehoon Park, Sukbok ChangAbstract:Described herein is the development of an unprecedented route to bridged sila-N-heterocycles via B(C6F5)3-catalyzed cascade silylation of N-aryl Piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) ��-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp2 C-H silylation. Copyright (c) 2018 American Chemical Societ
Prajesh S.volvoikar - One of the best experts on this subject based on the ideXlab platform.
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Protecting-Group-Directed Regio- and Stereoselective Oxymercuration–Demercuration: Synthesis of Piperidine Alkaloids Containing 1,2- and 1,3-Amino Alcohol Units
Synthesis, 2017Co-Authors: Santosh Tilve, Sandesh Bugde, Prajesh S.volvoikarAbstract:An efficient synthesis of naturally occurring 1,2- and 1,3-amino alcohol unit containing 2-substituted piperidine alkaloids and their analogues has been developed from l-pipecolinic acid. The protocol describes the regio- and stereoselective oxymercuration–demercuration of 2-alkenyl Piperidines based on protecting groups to give piperidine alkaloids as a key step.
Jianbo Zhang - One of the best experts on this subject based on the ideXlab platform.
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catalytic access to bridged sila n heterocycles from Piperidines via cascade sp3 and sp2 c si bond formation
Journal of the American Chemical Society, 2018Co-Authors: Jianbo Zhang, Sehoon Park, Sukbok ChangAbstract:Described herein is the development of an unprecedented route to bridged sila-N-heterocycles via B(C6F5)3-catalyzed cascade silylation of N-aryl Piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) β-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp2 C–H silylation.
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Catalytic Access to Bridged Sila‑N‑heterocycles from Piperidines via Cascade sp3 and sp2 C–Si Bond Formation
2018Co-Authors: Jianbo Zhang, Sehoon Park, Sukbok ChangAbstract:Described herein is the development of an unprecedented route to bridged sila-N-heterocycles via B(C6F5)3-catalyzed cascade silylation of N-aryl Piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) β-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp2 C–H silylation
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Catalytic Access to Bridged Sila- N-heterocycles from Piperidines via Cascade sp3 and sp2 C-Si Bond Formation
AMER CHEMICAL SOC, 2018Co-Authors: Jianbo Zhang, Sehoon Park, Sukbok ChangAbstract:Described herein is the development of an unprecedented route to bridged sila-N-heterocycles via B(C6F5)3-catalyzed cascade silylation of N-aryl Piperidines with hydrosilanes. Mechanistic studies indicated that an outer-sphere ionic path is operative to involve three sequential catalytic steps having N-silyl piperidinium borohydride as a resting species: (i) dehydrogenation of the piperidine ring, (ii) ��-selective hydrosilylation of a resultant enamine intermediate, and (iii) intramolecular dehydrogenative sp2 C-H silylation. Copyright (c) 2018 American Chemical Societ
Henry Y. Fadamiro - One of the best experts on this subject based on the ideXlab platform.
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quantitative analysis of alkaloidal constituents in imported fire ants by gas chromatography
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Hongyi Wei, Henry Y. Fadamiro, Li Zi-chenAbstract:A method based on silica gel chromatography and GC-MS/GC-FID analyses was developed for the quantitation of alkaloidal compounds in imported fire ants, Solenopsis richteri, S. invicta, and their hybrid found in the southern United States. The cis and trans alkaloids from fire ant body extracts were successfully separated by silica gel chromatography, identified by GC-MS, and quantitated by GC-FID. Piperideine compounds were eluted together with the cis and trans Piperidines, but were well-resolved on a nonpolar GC column. Eight pairs of piperidine isomers and 12 piperideines were quantitated. The ratios of trans alkaloids to corresponding cis isomers ranged from 87 to 378:1 in S. invicta and were significantly higher than in S. richteri and hybrid ants. The results were discussed in relation to the evolution of fire ant venom alkaloids and their role as host location cues for parasitic Pseudacteon phorid flies.
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Reduction of venom alkaloids in Solenopsis richteri×Solenopsis invicta hybrid: an attempt to identify new alkaloidal components.
Journal of agricultural and food chemistry, 2010Co-Authors: Li Zi-chen, Henry Y. FadamiroAbstract:The alkaloid chemistry of the venom of hybrid fire ant, Solenopsis richteri × Solenopsis invicta, was investigated using silica gel chromatography and GC-MS techniques. In addition to most cis alkaloids of parental species, S. richteri Forel and S. invicta Buren, the cis alkaloid fraction of the body extract of hybrid fire ants also contains five significant new alkaloids. Hydrogenation of the cis alkaloid fraction yielded only five Piperidines, 4', 12', 12, 20', and 20. Sodium borohydride and lithium aluminum hydride selectively reduced C═N double bond in piperideine alkaloids to give a mixture of cis and trans Piperidines. However, reduction of the five new components yielded several new peaks with much longer retention times and increasing molecular weights over 30. It is evident that the chemical identities of the five new peaks are quite different from those known Piperidines or piperideines found in Solenopsis fire ants.
Santosh Tilve - One of the best experts on this subject based on the ideXlab platform.
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Protecting-Group-Directed Regio- and Stereoselective Oxymercuration–Demercuration: Synthesis of Piperidine Alkaloids Containing 1,2- and 1,3-Amino Alcohol Units
Synthesis, 2017Co-Authors: Santosh Tilve, Sandesh Bugde, Prajesh S.volvoikarAbstract:An efficient synthesis of naturally occurring 1,2- and 1,3-amino alcohol unit containing 2-substituted piperidine alkaloids and their analogues has been developed from l-pipecolinic acid. The protocol describes the regio- and stereoselective oxymercuration–demercuration of 2-alkenyl Piperidines based on protecting groups to give piperidine alkaloids as a key step.
