Diorganozinc Compounds Research Articles

ChemInform Abstract: Functionalized Diorganozinc Compounds: Key Reagents for the Synthesis of Enantiomerically Pure 2,5‐Disubstituted cis‐ and trans‐ Tetrahydrofurans.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Influence of bulky substituents on the regioselective group-transfer reactions of diorganozinc compounds with N, N′-bis(2,6-di-isopropylphenyl)-1,4-diaza-1,3-butadiene

Diorganozinc compounds R 2Zn (R=alkyl or aryl) react with N,N′-bis(2,6-di-isopropylphenyl)-1,4-diaza-1,3-butadiene, (i-Pr 2Ph)NCHCHpN(i-Pr 2Ph) (i-Pr 2Ph-DAB) to give thermally unstable 1:1 coordination complexes R 2Zn(i-Pr2Ph-DAB), which subsequently undergo a slow regioselective alkyl or aryl group-transfer reaction from the zinc atom to an imine-nitrogen or a carbon atom of the NCCN system of the i-Pr 2Ph-DAB ligand. In the case of R=methyl, n-propyl, n-butyl, s-butyl, neopentyl and benzyl, C-alkylation occurs with a subsequent 1,2- hydrogen shift in the amino-imino skeleton affording RZn[(i-Pr 2Ph)N-CH 2-CRN(i-Pr 2Ph)], whereas for R=t- butyl the C-alkylated product t-BuZn[(i-Pr 2Ph)NCH(t-Bu)CHN(i-Pr 2Ph)] is stable. Surprisingly, diphenylzinc reacts with i-Pr 2Ph-DAB exclusively to give the N-arylated product PhZn[(i-Pr 2Ph)NCHCHN(Ph)(i-Pr 2Ph)].

Regioselective introduction of functional groups in α‐diimines by means of dialkylzinc compounds. Synthesis of functionalized 2‐ and 3‐pyrrolidinone derivatives

AbstractAlkylation of the 1,4‐diaza‐1,3‐butadiene t‐BuN=CH‐CH=N t‐Bu (t‐BuDAB) by functionally substituted diorganozinc compounds Zn[(CHR1XCH2)nXR2]2 (n = 1–3, R1 = H, Me, XR2 = OMe, OBn, SEt, NMe2, COOEt) occurs regioselectively. Alkylation occurs at the nitrogen atom of the N=C‐C=N skeleton of t‐BuDAB when primary diorganozinc compounds are used (R1 = H), but at the carbon atom when secondary and benzylic diorganozinc compounds are employed. The functional groups in the diorganozinc reagents proved to be important for the alkylation reaction only in the case of Zn[(CH2)3NMe2]2 (7) and Zn(C6H4CH2NMe2−2)2 (16), in which the strongly coordinating NMe2 groups give either a decrease of the alkylation rate (7), or no reactivity at all (16). When t‐BuDAB is reacted with Zn[(CH2)2COOEt]2 (10) alone, a 3‐pyrrolidinone (10c) is formed, whereas the same reaction with a mixture of 10 and ClZn(CH2)2COOEt affords a 2‐pyrrolidinone (10b). The reactions involve a two‐step process involving prior regioselective introduction of the alkyl group either at the N or C atom of an imine unit followed by an intramolecular nucleophilic substitution leading to 10b or 10c, respectively. The molecular structure of 10c shows the functionalized heterocycle to be part of a conjugated enamine system.

Formation of organozinc cations and anions from diorganozinc compounds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFormation of organozinc cations and anions from diorganozinc compoundsRonaldo M. Fabicon, Anthony D. Pajerski, and Herman G. Richey Jr.Cite this: J. Am. Chem. Soc. 1991, 113, 17, 6680–6681Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://doi.org/10.1021/ja00017a053RIGHTS & PERMISSIONSArticle Views168Altmetric-Citations39LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (308 KB) Get e-Alerts Get e-Alerts

Formation of organozincate ions from diorganozinc compounds and potassium alkoxides

Formation of organozincate ions from diorganozinc compounds and potassium alkoxides

ChemInform Abstract: The Preparation of (1‐(Arylimino)alkyl)zinc by the α‐Addition of Organozinc to Isocyanide.

AbstractThe diorganozinc compounds (I) are coupled with the isocyanate (II), forming the aldimines (III) after hydrolysis.

Gemischte organozinkverbindungen durch austauschreaktionen von diorganozinkverbindungen

Abstract The exchange of organyl groups between various diorganozinc compounds, R21Zn (R1 = CHMe2 (1), CH2(CH2)2Me (2), CH2C(Me)CH2 (3), CH2CHCHMe (4)) and R22Zn (R2 = Et (5), CH(Me)Et (6), CH2(CH2)3Me (7), CMe3 (8), Menthyl (9), Ph (10), Cyclohexyl (11)), has been followed by mass spectroscopy: molecular ions for the mixed compounds R1R2Zn were observed. The exchange equilibrium constants for 1–5 and 7–11 in toluene were shown calorimetrically to lie between 108 and 0.2. In contrast, the rates of exchange are comparable.

Synthesis, characterization and properties of some organozinc hydride complexes

The synthesis and characterization of the monopyridine complexes of ethylzinc hydride and phenylzinc hydride are described. On treatment with TMED these complexes are converted into R 2Zn 3H 4. TMED species through a combination of ligand-exchange and disproportionation. The formation of organozinc hydrides from ω-functionally-substituted diorganozinc compounds is only successful when the intramolecular coordination in these starting materials is weak and easily broken by pyridine. The results of these investigations are used as a basis for a discussion of the factors governing the formation of stable organozinc hydrides. The RZnH.py complexes easily reduce ketones and aldehydes, but no unusual stereoselectivity was observed in the reduction of substituted cyclohexanones. EtZnH.py reacts with an excess of pyridine with formation of the bis pyridine complex of ethyl(1,4-dihydro-1-pyridyl)zinc, a soluble compound, which is monomeric in benzene. The corresponding phenylzinc complex, however, cannot be isolated; disproportionation to Ph 2Zn.2py and the bis pyridine complex of bis(1,4-dihydro-1-pyridyl)zinc occurs.

Preparation and characterization of the pyridine complexes of ethylzinc hydride and phenylzinc hydride

The pyridine complexes of ethyizinc hydride and phenyLzinc hydride were prepared by treatment of the corresponding diorganozinc compounds with zinc hydride and two equivalents of pyridine in THF or benzene solution. Both complexes of the type RZnH·py, which were characterized by NMR spectroscopy, are trimeric in benzene solution.