The stereochemistry of organometallic compounds. Part V. Preferred conformations of tricarbonylmetal groups in some cis-tricarbonyl-(1-substituted indane)chromiums

Gracey, D. E. F.; Jackson, W. Roy; Jennings, W. Brian; Rennison, S. C.; Spratt, R.

doi:10.1039/j29690001210

Cited by 24 publications

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“…These electroneutral complexes are generally prepared by treating the cyclobutarene with complexation agents such as Cr(CO) 6 , (NH 3 ) 3 Cr(CO) 3 , (C 6 H 6 )Mo(CO) 3 , and (EtCN) 3 W(CO) 3 . Among the complexes reported, most are tricarbonylchromium complexes, − although a few reports describe tricarbonylmolybdenum and tricarbonyltungsten complexes. 405a, Some representative examples are illustrated in Table .…”

Section: Synthesismentioning

confidence: 99%

Cyclobutarenes and Related Compounds

2003

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A general method for the synthesis of cyclobutarenes involves 1,4-elimination from adjacent benzylic positions, followed by ring closure of the resulting o-quinodimethane. The earliest report in which an o-quinodimethane was implicated was the reaction of R,R,R′,R′-tetrabromo-o-xylene (4) with iodide to give the 1,2-dibromocyclobutarene 6, via o-quinodimethane 5. Treatment of 6 with NaI in acetone gave diiodide 7, which on catalytic reduction gave 1 (Scheme 1). [15][16][17] Cava and co-workers confirmed that 5 was an intermediate by trapping experiments using sev-eral dienophiles. 18 A similar procedure has been used to prepare 1,2-diphenylcyclobutarene. 19 Heterocyclic analogues may also be prepared by the 1,4-elimination of halogen from suitable precursors. Compounds 9 and 11 have been synthesized from 8 and 10, respectively, as illustrated in Scheme 2. 20 A variation of the method involves the conversion of R-alkyl-R-bromosulfones into cyclobutarenes using tetrabutylammonium fluoride (TBAF) in acetonitrile at 20-25 °C to effect the elimination. 21 The desired cyclobutarene is often accompanied by olefinic side products, as illustrated in the preparation of cyclobutarene 13, which is accompanied by 14 (eq 1) (Table 1). Anil K. Sadana was born in Panipat, India. He did his M.Sc (1990) and M. Phil (1992) from Kurukshetra University, India. He obtained his Ph.D. degree in 1999 under the guidance of Prof. Om Prakash. His Ph.D. work focused on the utility of hypervalentiodine reagents in the synthesis of heterocyclic compounds. He then joined Prof. W. E. Billups lab as postdoctoral research associate in 2000. He is presently working on small ring compounds and carbon nanotubes. Rajesh Kumar Saini was born in 1966 in Ambala, India. He received his masters degree in 1989 and his Ph.D. in 1996 from Kurukshetra University, India. After his doctorate he moved to the United States for his postdoctoral studies. After a brief stay at Sam Houston State University he joined Rice University, where he is working as a Research Scientist in the laboratories of Prof. W. E. Billups and Prof. Richard E. Smalley. His research has concentrated on small ring compound and the development of carbon nanotube chemistry. W. E. Billups was born in 1939 in Huntington, West Virginia. He received his B.S. in Chemistry Degree from Marshall University in 1961. This was followed by a period in industry after which he entered the graduate school of the Pennsylvania State University in 1968 and received the Ph.D. in 1970. He then joined the chemistry department at Rice University. He served as the Department Chair from July 1985 until December 1991. His research interests are divided among the areas of small-ring compounds, reactive intermediates, chemistry of free metal atoms and more recently fullerene and carbon nanotube chemistry.

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Section: Synthesismentioning

confidence: 99%

Cyclobutarenes and Related Compounds

2003

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“…However, a good affinity is regained when the 3-hydroxyl function is maintained away from the steroid skeleton by a spacer chain (-0-(CH2)3-) 17. It appears also that the fixation site of the tripod on the A ring of the steroid stroly discriminates the ct and diastereomers with respect to their recognition properties, While the s-isomers (11,19) show relatively modest affinities, the ct-isomers (10,12,18) ;IIIIIyI With labelled oestrogens used to measure the oestrogen receptor content of breast tumor samples, non-receptor binding can reduce the sensitivity of the assay procedure. In order to prove the specific association of the chromium-labelled steroids for the oestradiol receptor site, we prepared compound 18 tritium labelled at the l7ct-position (scheme 9)and performed in vitro incubation experiints (Table 2).…”

Section: Model Of Steroid Hormone Actionmentioning

confidence: 99%

“…At first sight, one might have visualized that the -complexed molecules should be sterically disfavored because of non-bonded interactions between the tripod and the methyl group at C-13 ; indeed, the behaviour of the Cr(CO)3 complexes of the methylindanes supports this idea (ref. 18). However, the relative yields of a-to s-isomers do not reflect the supposed importance of this steric effect.…”

Section: Model Of Steroid Hormone Actionmentioning

confidence: 99%

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Transition metal carbonyl oestrogen receptor assay

Jaouen¹,

Vessières²

1985

Pure and Applied Chemistry

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-Hormonal steroids, such as 17 -estradio1 derivatives, labelled with organometallic moieties have been synthesized and tested as markers for hormone receptor assay. Among the organometallic labels used were : Cr(C0) and Cr(C0)9(CS) which5can be attached to the arene A ring of the sterid ; Co9(C06 and Mo(rì -CH)9(C0)4 which can be bonded to acetylenic groups introduced at the 17c-p6sWton o the flve'-membered steroidal ring. There is a spectral window at about 2000 cm' in the FT-IR spectra of the protein precipitated from lamb uterus cytosol which we reasoned could be used to detect the v(C0) modes of the metal carbonyl fragments of the organometallic labels. This indeed proved possible and the present detection level for 10,000-20,000 co-added scans at 4cm1 resolution is in the neighborhood of 100 fM. That specific rather than non-specific receptor sites were being detected was demonstrated by preparing an estradiol derivative doubly labelled with tritium and Cr(C0)3 and comparable receptor-site concentration levels were measured by both radiochemical analysis and FI-IR spectroscopy. The potential application of this new receptor assay technique in the early diagnosis of hormonedependent cancers appears feasible.

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Organometallic Derivatives

ButenschÃ¶n

2009

Patai's Chemistry of Functional Groups

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The stereochemistry of organometallic compounds. Part V. Preferred conformations of tricarbonylmetal groups in some cis-tricarbonyl-(1-substituted indane)chromiums

Cited by 24 publications

References 0 publications

Cyclobutarenes and Related Compounds

Cyclobutarenes and Related Compounds

Transition metal carbonyl oestrogen receptor assay

Organometallic Derivatives

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