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Full-Text Articles in Physical Sciences and Mathematics
Nicholas Reactions Of Alkynyl- And Alkenyltrifluoroborates, Brent St. Onge, James R. Green
Nicholas Reactions Of Alkynyl- And Alkenyltrifluoroborates, Brent St. Onge, James R. Green
Chemistry and Biochemistry Publications
The Lewis acid mediated Nicholas reaction of potassium alkynyltrifluoroborates and propargyl acetate- hexacarbonyldicobalt complexes affords 1,4-diyne dicobalt hexacarbonyl complexes in good yields. The analogous Nicholas reactions of potassium alkenyltrifluoroborates give 1,3-enyne dicobalt hexacarbonyl complexes in most cases, although the initial site of reaction can vary. Potassium vinyltrifluoroborate itself affords alkynylcyclopropane complexes.
Alkynedicobalt Complexes In Γ-Carbonyl Cations And Cycloheptynedicobalt Complexes, James R. Green
Alkynedicobalt Complexes In Γ-Carbonyl Cations And Cycloheptynedicobalt Complexes, James R. Green
Chemistry and Biochemistry Publications
This Account describes our work on highly electrophilic γ-carbonyl cations featuring propargyldicobalt cations, cycloheptynedicobalt complexes, and the interconnection between the two systems.
1 Introduction
2 γ-Carbonyl Cations via Iron Allyl Cations
3 γ-Carbonyl Cations via Propargyldicobalt Cations
3.1 Synthesis of Velloziolide
3.2 Synthesis of Microstegiol
4 Synthesis of Cycloheptynedicobalt Complexes
4.1 Synthesis via γ-Carbonyl Cations
4.2 Cycloheptynedicobalt Complexes via [4+3] Cycloaddition Reactions
4.3 Cycloheptynedicobalt Complexes via Ring-Closing Metathesis
4.4 Cycloaddition Reactions on Cycloheptynedicobalt Complexes
4.5 Cycloheptynedicobalt Complexes via Intramolecular Nicholas Reactions
5 Dehydrotropylium Ion Co2(CO)6 Complex
6 Final Comments
Vinylogous Nicholas Reactions In The Synthesis Of Icetexane, Faveline, And Related Ring Systems, Izabela Kolodziej, James R. Green
Vinylogous Nicholas Reactions In The Synthesis Of Icetexane, Faveline, And Related Ring Systems, Izabela Kolodziej, James R. Green
Chemistry and Biochemistry Publications
The intramolecular vinylogous Nicholas reactions of aryl substituted acetoxy enyne-Co(2)(CO)(6) complexes afford tricyclic 6,7,6-ring systems and related systems in good yield.
Cyclohepta[De]Naphthalenes And The Rearranged Abietane Framework Of Microstegiol Via Nicholas Reaction Chemistry, Rafiq A. Taj, Anusha Abhayawardhana, James R. Green
Cyclohepta[De]Naphthalenes And The Rearranged Abietane Framework Of Microstegiol Via Nicholas Reaction Chemistry, Rafiq A. Taj, Anusha Abhayawardhana, James R. Green
Chemistry and Biochemistry Publications
Nicholas reactions on 2,7-dioxygenated naphthalenes give C-1 monosubstitution and C-1/C-8 disubstitution in most cases. From gamma-carbonyl cation monocondensation product 3b or alkyne-unsubstituted dicondensation product 4a, cyclohepta[de]naphthalenes bearing no substituents, gem-dimethyl substituents, and a ketone function, and the rearranged abietane framework of microstegiol may be prepared.
Tandem 4+3 Cycloaddition/Nucleophilic Trapping Reactions Of Butyne-1,4-Diether Dicobalt Hexacarbonyl Complexes, Yafan Lu, James R. Green
Tandem 4+3 Cycloaddition/Nucleophilic Trapping Reactions Of Butyne-1,4-Diether Dicobalt Hexacarbonyl Complexes, Yafan Lu, James R. Green
Chemistry and Biochemistry Publications
Butyne-1,4-diether hexacarbonyldicobalt complexes 1 undergo Lewis acid mediated 4+3 cycloadditions with allylsilanes, incorporating halide from the Lewis acid to give halocycloheptynes 3, 6, 7. A phenyl group may be incorporated in place of the halogen (to give 8) by use of benzene as solvent and with B(C6F5)(3) as the Lewis acid; chlorobenzene and toluene also participate in the process.
Cycloheptenyne Dicobalt Hexacarbonyl Complexes By Ring Closing Metathesis, James R. Green
Cycloheptenyne Dicobalt Hexacarbonyl Complexes By Ring Closing Metathesis, James R. Green
Chemistry and Biochemistry Publications
Hexacarbonyldicobalt complexes of cycloheptenynes (4) may be prepared by the ring closing metathesis of the corresponding acyclic dienes (2) using Grubbs' catalyst, (Cy3P)(2)Cl2Ru=CHPh. A cyclooctenyne complex (8) has also been prepared in the strictly analogous manner.