Reagents RCu Research Articles

ChemInform Abstract: Alkylation of Some Tricarbonyl(pentadienyl)- and (Cyclohexadienyl)iron( +1) Salts with the Highly Functionalized Copper Reagents RCu(CN)ZnI.

Abstract Reaction of the highly functionalized copper reagents RCu(CN)ZnI with the title compounds occurs predominantly at less hindered termini, generating functionalized side chains at C5 of (η4-penta-1,3-diene) and (η4-clohexa-1,3-diene)tricarbonyliron(0) complexes.

Stereoselective Synthesis of Chiral 3-Aryl-1-alkynes from Bromoallenes and Heterocuprates

The synthesis of chiral 3-aryl-1-alkynes 3 via cross-coupling of 3-alkyl- and 3,3-dialkyl-1-bromo-1,2-dienes 1 and arylbromocuprates (RCuBr)MgBr.LiBr 2 was examined. With phenylcopper reagents and its para-substituted derivatives, as well as with 2-naphthyl cuprates, the reaction gave compounds 3 with high regioselectivity and good yields on the chemically pure product. On the contrary, when ortho-substituted phenyl reagents and 1-naphthyl cuprates were used, the regioselectivity of the process was very dependent upon the steric requirements of the alkyl substituents on the bromoallenic substrate. When the steric bulk was increased, remarkable quantities of isomeric arylallenes 4 were also observed in the reaction mixtures. The high 1,3-anti stereoselectivity of the coupling process allowed us to obtain enantiomerically enriched 3-aryl-1-alkynes from optically active allenic substrates, thus indicating a simple pathway toward the synthesis of quaternary stereogenic centers characterized by an aryl group. A possible cross-coupling mechanism was also suggested to explain the regio- and stereochemical data. For the preparation of omega-functionalized 3-phenyl-1-alkynes, the reaction of 1-bromo-3-phenylpropadiene with Knochel reagents RCu(CN)ZnCl.2LiCl was also studied; this reaction led to the acetylenic compounds in high yields mainly when the R group (also omega-functionalized) on the copper reagent was primary.

Additions of Organocopper Reagents and Heteroatom Nucleophiles to 1-Phenylseleno-2-(p-toluenesulfonyl)ethyne. Preparation of Vinyl and Allenic Sulfones and Formation of Michael, Anti-Michael, and Rearrangement Products

1-Phenylseleno-2-(p-toluenesulfonyl)ethyne (4) was produced nearly quantitatively from p-(toluenesulfonyl)ethyne and benzeneselenenyl chloride. It underwent stereo- and regioselective syn-additions of organocopper reagents RCu(CN)Li to the β-position of the sulfone moiety to afford adducts 5. Further reaction of the products with reagents RCu(SePh)Li resulted in substitution of the phenylseleno group with retention of configuration. Control of E,Z-stereochemistry in the product β,β-disubstituted vinyl sulfones is therefore achieved by the order of addition of the reagents. Selenoxide syn-elimination of adducts 5 afforded the corresponding allenic sulfones. The additions of amines and alkoxides to 4 produced the corresponding anti-Michael regioisomers (where attack occurred α to the sulfone group) as the major or sole products. The additions were highly stereoselective, proceeding by anti-addition in the anti-Michael series and by syn-addition in the corresponding Michael regioisomers. The reactions of 4 with thiolates and selenolates were more complex, affording rearranged adducts and Michael adducts as the major and minor products, respectively. The formation of the rearranged products can be rationalized by a series of addition−elimination processes. Phenylselenoethyne (43) underwent conjugate additions of pyrrolidine, sodium methoxide, sodium ethanethiolate, and benzeneselenolate anion, affording the corresponding cis isomers via anti-addition. The experiments with heteroatom nucleophiles and acetylenes 4 and 43 show that the phenylseleno group has a surprisingly large activating effect upon conjugate additions.

Molybdenum-mediated diastereoselective synthesis of 2-heterobicyclo[4.4.0]decene derivatives

The addition of a variety of functionalized zinc–copper reagents RCu(CN)ZnI 2 to (η5-cyclopentadienyl)(η4-cyclohexa-1,3-diene)dicarbonylmolybdenum cation 1 proceeds in a highly regio- and stereo-specific fashion to generate (η5-cyclopentadienyl)(π-allyl)dicarbonylmolybdenum complexes 3 with a functionalized side-chain at the C-4 position of the ring. Intramolecular cyclization of the (π-allyl)molybdenum complexes containing a pendant alcohol, carboxylic acid, thiol or amine functionality affords fused 2-heterobicyclo[4.4.0]decene derivatives.

Transition Metal Cation Salts in Organic Synthesis

AbstractReaction of lithium diisopropylamide (LDA) with (η4‐1,3‐cyclohexadiene)Fe(CO)3 complexes bearing functionalized side chains at C‐5, under an atmosphere of carbon monoxide, gives bridged bicyclo[3,2,1]octene and bicyclo[3,3,1]nonene systems after electrophilic quenching. Under the same reaction conditions, intramolecular cyclization of acyclic (η4‐ 1,3‐butadiene)Fe(CO)3 complexes with functionalized side chains at the terminal position of the diene ligands furnishes fused bicyclo[3.3,0]octanone and bicyclo[4.3.0]nonanone derivatives after acid quenching. The addition of a variety of the highly functionalized zinc‐copper reagents RCu(CN)ZnI to the (η7‐cycloheptatrienyl)Cr(CO) gives (η6‐cyclohepta‐1,3,5‐triene)Cr(CO)3 complexes with a functionalized side‐chain at the C‐7 position of the ring. Intramolecular cyclization of ester‐subsbtuted adducts using lithium diisopropylamide generates fused bicyclo[5.3.0]decane and bicyclo[5.4.0]undecane derivatives. The addition of a variety of the highly functionalized zinc‐copper reagents RCu(CN)Znl to the (η4‐cyclohexa‐1,3‐diene)Mo(CO)2(Cp) at the terminus of the coordinated diene ligand gives [Mo(π‐allyl)(CO)2(Cp)](Cp = cyclopentadienyl) complexes with the functionalized side‐chain at the C‐4 position of the ring. Intramolecular cyclization of the (π‐allyl)molybdenum complex containing a pendant propanoic acid unit generates the δ‐lactone derivative.

Michael Addition Reactions of the Highly Functionalized Zinc-Copper Reagents RCu(CN)ZnI to (Tropone)iron Tricarbonyl Promoted by Boron Trifluoride Etherate

Michael Addition Reactions of the Highly Functionalized Zinc-Copper Reagents RCu(CN)ZnI to (Tropone)iron Tricarbonyl Promoted by Boron Trifluoride Etherate

Construction of fused bicyclo-[5.3.0]decane and -[5.4.0]undecane ring skeletons via sequential additions of nucleophiles to tricarbonyltropyliumchromium tetrafluroborate

The addition of a variety of the highly functionalized zinc–copper reagents RCu(CN)ZnI to the title cation gives (η6-cyclohepta-1,3,5-triene)Cr(CO)3 complexes with a functionalized side chain at the C-7 position of the ring: intramolecular cyclisation of ester-substituted adducts using lithium diisopropylamide generates fused bicyclo-[5.3.0]decane and -[5.4.0]undecane derivatives.

Nucleophilic Addition to (η3-Allyl)Fe(CO)4Cations with Functionalized Zinc-Copper Reagents RCu(Znl)CN

Regioselectivity of the addition of the highly functionalized zinc-copper reagents to (η3-allyl)Fe(CO)4 cationic salts was studied. For 1,1-disubstituted allyl cation 1, the zinc-copper reagents added predominantly at the unsubstituted terminus. For 1,1,2-trisubstituted allyl cation 2, reactive zinc-copper reagents attacked mainly at the unsubstituted terminus while less reactive zinc-copper reagents added to a coordinated CO ligand. For 1,1,3-trisubstituted allyl cation 3, the addition occurred at both the less substituted allyl terminus and a coordinated CO ligand.

Preparation of polyfunctional nitro olefins and nitroalkanes using the copper-zinc reagents RCu(CN)ZnI

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation of polyfunctional nitro olefins and nitroalkanes using the copper-zinc reagents RCu(CN)ZnICarole Jubert and Paul KnochelCite this: J. Org. Chem. 1992, 57, 20, 5431–5438Publication Date (Print):September 1, 1992Publication History Published online1 May 2002Published inissue 1 September 1992https://doi.org/10.1021/jo00046a027RIGHTS & PERMISSIONSArticle Views611Altmetric-Citations57LEARN 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 (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Alkylation of the (η4-cyclohexa-1,3-diene)(η5-cyclopentadienyl)(dicarbonyl)-molybdenum hexafluorophosphate with the highly functionalized zinc–copper reagents RCu(CN)Znl

The addition of a variety of the highly functionalized zinc–copper reagents RCu(CN)Znl to the title cation at the terminus of the coordinated diene ligand gives [Mo(π-allyl)(CO)2(Cp)](Cp = cyclopentadienyl) complexes with the functionalized side-chain at the C-4 position of the ring: intramolecular cyclisation of the (π-allyl)molybdenum complex 4 containing a pendant propanoic acid unit generates the δ-lactone derivative 6.

Reactions of (η3-allyl)tetracarbonyliron cations with the highly functionalized copper reagents RCu(CN)Znl

The addition of the highly functionalized copper reagents RCu(CN)Znl to (η3-allyl)Fe(CO)4 cations occurs mainly at the unsubstituted allyl terminus to yield the functionalized isoprenyl derivatives; with substituents on both ends of the allyl, the regular isoprenyl adducts are isolated together with ketone products which are derived from nucleophilic additions to the carbon monoxide ligands.

Alkylation of some tricarbonyl(pentadienyl) and (cyclohexadienyl)iron(+1) salts with the highly functionalized copper reagents RCu(CN)ZnI

Reaction of the highly functionalized copper reagents RCu(CN)ZnI with the title compounds occurs predominantly at less hindered termini, generating functionalized side chains at C5 of (η 4-penta-1,3-diene) and (η 4-clohexa-1,3-diene)tricarbonyliron(0) complexes.

ChemInform Abstract: The Addition of the Highly Functionalized Zinc Copper Reagents RCu(CN)ZnI to Nitro Olefins.

stereochemical control than the more common trimethylsilyl unit. For example, the condensation of allylic zinc reagents with benzoyl triisopropylsilane produced the a-adduct exclusively. The overall applicability of the process is quite broad.1° Similar results were obtained using a$-unsaturated or aliphatic aldehydes, with organozinc, magnesium, lithium,loaJ1 or potassium reagents. Some of our results are shown in Table 11. Noteworthy is the example that condensation of cis-2pentenyl p o t a s s i ~ m ' ~ J ~ prepared from cis-2-pentene, po-

ChemInform Abstract: The Reactivity of the Highly‐Functionalized Copper Zinc Reagents RCu(CN)ZnI Toward 1‐Haloalkynes and Acetylenic Esters.

AbstractThe mixed organozinc cuprates (III) are coupled with the 1‐bromo‐1‐alkynes (IV) to yield the acetylenic compounds (V).

S N2′ Substitutions of 1,3-Dichloropropenes with the Functionalized Copper-Zinc Reagents RCu(CN)ZnX

The addition of benzenesulfenyl (or benzeneselenyl) chlorides to propargylic chlorides affords regio- and stereospecifically (E)-1,3-dichloro-2-phenylsulfenyl (or phenylselenyl) propenes (2a-c). These new reagents were found to react with excellent S N2′ selectivity with the highly functionalized copper-zinc reagents RCu(CN)ZnX, affording polyfunctional vinylic-thioethers or -selenides of type 3. The acidic hydrolysis of 3 furnishes symmetrical ketones in good yields.

The addition of the highly functionalized zinc-copper reagents RCu(CN)ZnI to nitro olefins

stereochemical control than the more common trimethylsilyl unit. For example, the condensation of allylic zinc reagents with benzoyl triisopropylsilane produced the a-adduct exclusively. The overall applicability of the process is quite broad.1° Similar results were obtained using a$-unsaturated or aliphatic aldehydes, with organozinc, magnesium, lithium,loaJ1 or potassium reagents. Some of our results are shown in Table 11. Noteworthy is the example that condensation of cis-2pentenyl p o t a s s i ~ m ' ~ J ~ prepared from cis-2-pentene, po-

ChemInform Abstract: 1,4‐Additions of the Highly Functionalized Copper Reagents RCu(CN)ZnI·2BF3 to Trisubstituted Enones. A New BF3‐Promoted Cyclization Reaction.

AbstractThe complex copper‐zinc organometallics (IIIa) ‐ (IIId), synthesized from the corresponding zinc organometallics (I), react with the α,β‐unsaturated ketones (IV) to give the Michael‐type adducts (V).

The reactivity of the highly functionalized copper, zinc reagents RCu(CN)ZnI toward 1-haloalkynes and acetylenic esters

The highly functionalized organometallics RCu(CN)ZnI 1 react efficiently with 1-haloalkynes providing polyfunctionalized alkynes in high yields. This method has been used to prepare a pheromone of the Amathes c-nigrum in 3 steps and 64% overall yield. The reagents 1 also add in the presence of an excess of Me 3SiCl to acetylenic esters to afford polyfunctionalized C—silylated ethylenic esters. In the case of ethyl propiolate, the reaction is highly stereoselective and affords 97% pure (E)-2-trimethylsilyl ethylenic esters.

ChemInform Abstract: Synthesis and Reactivity Toward Acyl Chlorides and Enones of the New Highly Functionalized Copper Reagents RCu(CN)ZnI.

Les composes du titre sont prepares par transmetallation a partir d'iodures d'alkyl zinc et du sel CuCN•2LiX. Ils reagissent sur des chlorures d'acyle et des enones pour donner des cetones et des produits d'addition 1,4

Synthesis and reactivity toward acyl chlorides and enones of the new highly functionalized copper reagents RCu(CN)ZnI

Les composes du titre sont prepares par transmetallation a partir d'iodures d'alkyl zinc et du sel CuCN•2LiX. Ils reagissent sur des chlorures d'acyle et des enones pour donner des cetones et des produits d'addition 1,4