scholarly journals Intramolecular Cyclization of Ruthenium Vinylidene Complexes with a Tethering Vinyl Group:  Facile Cleavage and Reconstruction of the C−C Double Bond

2007 ◽  
Vol 129 (48) ◽  
pp. 14974-14980 ◽  
Author(s):  
Cheng ◽  
Yi-Chun Kuo ◽  
Shu-Hao Chang ◽  
Ying-Chih Lin ◽  
Yi-Hong Liu ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Vinylidene Complexes ◽  
Vinyl Group

Unprecedented Formation of μ-Vinylidene Complexes from Phospharuthenocene and Acyl Chloride via Activation of the CO Double Bond

2007 ◽  
Vol 26 (27) ◽  
pp. 6698-6700 ◽  
Author(s):  
Masamichi Ogasawara ◽  
Takeshi Sakamoto ◽  
Azumi Ito ◽  
Yonghui Ge ◽  
Kiyohiko Nakajima ◽  
...  
Keyword(s):  
Double Bond ◽  
Acyl Chloride ◽  
Vinylidene Complexes

The photochemistry of aliphatic and alicyclic α,β-unsaturated nitro compounds. A study of double bond cleavage following intramolecular cyclization and nitro-nitrite rearrangement

1984 ◽  
Vol 37 (6) ◽  
pp. 1231 ◽  
Author(s):  
RD Grant ◽  
JT Pinhey
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Methyl Acrylate ◽  
Room Temperature ◽  
Bond Cleavage ◽  
Nitro Compounds ◽  
Significant Extent ◽  
Cleavage Reaction ◽  
Nitrile Oxides ◽  
Bond Cleavage Reaction

The light-induced intramolecular cyclization of α, β-unsaturated nitro compounds leading to double bond cleavage, which had previously been detected in a small number of β-nitrostyrenes and α-nitro-stilbenes, has been shown to occur in a range of aliphatic and alicyclic α, β -unsaturated nitro compounds. At room temperature the reaction competes to a significant extent with the well known nitro-nitrite rearrangement in the irradiation of 1-nitro-2-phenylcyclohexene (2), 1-methyl-2-nitro-cyclohexene (6), 1-methyl-2-nitrocycloheptene (11), 2-methyl-3-nitrobut-2-ene (23) and 2-nitro-3-phenylbut-2-ene (24), while it was the only reaction detected in the case of 1-methyl-2-nitrocyclo- octene (12) and 1-nitrocyclooctene (19). No evidence for the cleavage reaction was found with 1-methyl-2-nitrocyclopentene (10), 1-nitrocyclohexene (17), 1-nitrocycloheptene (18) and 3-nitropent-2-ene (25). The nitrile oxides produced in the double bond cleavage reaction were trapped in a cycloaddition with methyl acrylate, yielding 3-substituted methyl 4,5-dihydroisoxazole-5-carboxylates. Irradiations of 1-methyl-2-nitrocyclohexene (6) and 1-methyl-2-nitrocycloheptene (11) in refluxing benzene afforded only the bridged ring isoxazolines (30) and (31) respectively. Syntheses of a number of nitro-olefins are also reported.

Intramolecular Cyclization of Phenol Derivatives with C=C Double Bond in a Side Chain.

ChemInform ◽  
2007 ◽  
Vol 38 (20) ◽  
Author(s):  
Yoshihiko Ito ◽  
Risa Kato ◽  
Kentaro Hamashima ◽  
Yohei Kataoka ◽  
Yohei Oe ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Side Chain ◽  
Phenol Derivatives

scholarly journals Intramolecular Metathesis of a Vinyl Group with Vinylidene CC Double Bond in Ru Complexes

2005 ◽  
Vol 127 (51) ◽  
pp. 18037-18045 ◽  
Author(s):  
Yung-Sheng Yen ◽  
Ying-Chih Lin ◽  
Shou-Ling Huang ◽  
Yi-Hung Liu ◽  
Hui-Ling Sung ◽  
...  
Keyword(s):  
Double Bond ◽  
Ru Complexes ◽  
Vinyl Group

Intramolecular cyclization of phenol derivatives with CC double bond in a side chain

2007 ◽  
Vol 692 (1-3) ◽  
pp. 691-697 ◽  
Author(s):  
Yoshihiko Ito ◽  
Risa Kato ◽  
Kentaro Hamashima ◽  
Yohei Kataoka ◽  
Yohei Oe ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Side Chain ◽  
Phenol Derivatives

Stereoselective synthesis of dioxabicycles from 1-C-allyl-2-O-benzyl-glycosides — An intramolecular cyclization between 2-O-benzyl oxygen and the allyl double bond

2006 ◽  
Vol 84 (4) ◽  
pp. 597-602 ◽  
Author(s):  
An-Tai Wu ◽  
Tian Yi ◽  
Huawu Shao ◽  
Shih-Hsiung Wu ◽  
Wei Zou
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Stereoselective Synthesis ◽  
Carbonium Ion

Addition of a proton to the double bond of 1-C-allyl-O-benzylglycosides gave a 2′-carbonium ion, which in turn reacted intramolecularly, in a regio- and diastereo-selective manner, with the nucleophilic oxygen of the 2-O-benzyl group to form an oxonium intermediate. Subsequent cleavage of the benzyl C—O bond led to dioxabicycles in moderate yields. Surprisingly, opposite diastereoselectivities were observed from 1-C-allylglycofuranosides and 1-C-allylglycopyranosides, which produced 2,2′-trans- and 2,2′-cis-dioxabicycles, respectively.Key words: C-glycoside, olefin, cyclization, oxocarbonium, dioxabicycles.

Intermolecular Dehydrative Coupling and Intramolecular Cyclization of Ruthenium Vinylidene Complexes Formed from Aromatic Propynes Containing Carbonyl Functionalities

2018 ◽  
Vol 13 (24) ◽  
pp. 3885-3894 ◽  
Author(s):  
Pi-Yeh Chia ◽  
Cheng-Chen Kuo ◽  
Shou-Ling Huang ◽  
Yi-Hong Liu ◽  
Ling-Kang Liu ◽  
...  
Keyword(s):  
Intramolecular Cyclization ◽  
Vinylidene Complexes

scholarly journals Concerning the structure of photobilirubin II

1982 ◽  
Vol 201 (1) ◽  
pp. 179-188 ◽  
Author(s):  
M S Stoll ◽  
N Vicker ◽  
C H Gray ◽  
R Bonnett
Keyword(s):  
Double Bond ◽  
Starting Material ◽  
Vinyl Group

Evidence is presented which supports the postulate that the photobilirubins IIA and IIB are diastereoisomers in which the C-3 vinyl group has cyclized intramolecularly. The evidence comes principally from proton n.m.r. spectroscopy at 400 MHz and from chemical considerations. The cyclic structures require the E-configuration at the C-4 double bond in the precursor; this is the first structural evidence for the Z leads to E isomerization in bilirubin and supports the view that the precursor (photobilirubin IA or IB) is (4E, 15Z)-bilirubin. Brief irradiation of photobilirubin II gives bilirubin, a new compound (photobilirubin III) and unchanged starting material. The various photoisomers are discussed in terms of their inter-relationships and biological fates.

Electrophilic additions to 10β-vinyl cholestane derivatives

1983 ◽  
Vol 48 (10) ◽  
pp. 2994-3019 ◽  
Author(s):  
Pavel Kočovský ◽  
Ivo Starý ◽  
František Tureček ◽  
Vladimír Hanuš
Keyword(s):  
Reaction Mechanism ◽  
Double Bond ◽  
Hydroxyl Group ◽  
Acid Addition ◽  
Hypobromous Acid ◽  
Markovnikov Rule ◽  
Vinyl Group ◽  
Electrophilic Additions

Hypobromous acid addition to steroid dienes I-VI proceeds in four steps. The reaction commences by the attack on more reactive endocyclic double bond from the α-side yielding intermediary diaxial bromohydrins XXVIII, XXXIV, XL, XLIV, L and LVI via corresponding α-bromonium ions. The 10β-vinyl group of the bromohydrins then reacts with a second equivalent of the reagent forming transient 19-epimeric bromonium ions. The ions generated from I, II, V and VI are cleaved intramolecularly by the hydroxyl group, in accordance with the Markovnikov rule, giving rise to 19-epimeric dibromo epoxides XXXIa and XXXIIa, XXXVII and XXXVIII, LIIIa and LIVa, LIX and LX. By contrast, the ions generated from III and IV are cleaved in an anti-Markovnikov manner to yield dibromo epoxides XLII, XLVII and XLVIII. Products due to formation of a new C-C bond were not observed. The reaction mechanism and differences in the behaviour of the dienes I-VI are discussed.

Sign in / Sign up

Export Citation Format

Share Document