Dale W. Lichtenberg

Reactions of coordinated propargyl and allene ligands in cyclopentadienyliron dicarbonyl complexes

Abstract Reactions of η5-C5H5Fe(CO)2CH2CCR (R  CH3, C6H5, and CH2Fe(CO)2(η5-C5H5)) with HBF4 in acetic anhydride yield [η5-C5H5Fe(CO)2(η2CH2CCHR)]+BF−4. The resultant cationic iron-η2-allene complexes react with a wide range of nucleophiles (Nu) to give the following types of behavior: (a) addition of Nu to carbon-1 of the η2-allene fragment (with NaBH4, (C2H5)2NH, and P(C6H5)3, inter alia), (b) addition of Nu to carbon-2 of the η2-allene fragment (with NaOCH3), (c) addition of Nu to the carbonyl carbon (with NaOC2H5), (d) deprotonation of the iron-η2-allene cation to the parent propargylic complex (with N(C2H5)3), and (e) nonselective reactions to yield a mixture of products (with CH3Li). Of these, the most common is behavior (a); together with the protonation of η5-C5H5Fe(CO)2CH2CCR it stimulates the two-step (3 + 2) cycloaddition reactions between electrophilic molecules and these iron-propargyl complexes.

Cycloaddition Reactions of transition metal-2-alkynyl complexes with diphenylketene, t-butylcyanoketene, N-sulfinylaniline, and N-Sulfinyl-p-toluenesulfonamide

Abstract The reactions of η 5 -C 5 H 5 Fe(CO) 2 CH 2 CCR (R = CH 3 CP 6 H 5 , and CH 2 Fe(CO) 2 ,(η 5 -C 5 H 5 ), η 5 -C 5 H 5 -Mo(CO) 3 CH 2 CCC 6 H 5 , and Mn(CO) 5 CH 2 CCC 6 H 5 ([M] CH 2 CCR) with the ketenes (C 6 H 5 ) 2 CCO and (t-C 4 H 9 (CN)CCO and with the N-sulfinyl compounds C 6 H 5 NSO and p-CH 3 C 6 H 4 SO 2 NSO result in the formation of (3 + 2) cycloadducts of the reactants. The respective products of these reactions are [M] CC(R)C(O)C(C 6 H 5 ) 2 C H 2 , [M] CC(R)C(O)Ct-C 4 H 9 (CN)C H 2 , [M] CC(R)S (O)N(C 6 H 5 )CH 2 , and [M] CC(R)S(O)N(SO 2 C 6 H 4 CH 3 )CH 2 . These structures have been elucidated on the basis of infrared, 1 H NMR, and 13 C NMR spectroscopic data. No reactions were observed bet- ween η 5 -C 5 H 5 Fe(CO) 2 CH 2 CCCH 3 and C 2 H 5 O 2 CNNCO 2 C 2 H 5 and between η 5 -C 5 H 5 Fe(CO) 2 R (R = CH 3 and CH 2 C 6 H 4 OCH 3 -p) and the two ketenes.

Reactions of transition metal-2-alkynyl complexes with sulfur trioxide. Organometallic sultone complexes

Abstract A series of transition metal-vinyl complexes containing a sultone ring have been prepared by the reaction of the corresponding metal-2-alkynyl complexes with SO3 dioxane or uncomplexed SO3. The new compounds include h5-C5H5Fe(CO)2 CC(R)S(O) 2 OC H2 (R = CH3, C6H5), h5C5H5Mo(CO)3 CC(R)S(O) 2 OC H2 (R = C6H5) and Mn(CO)5 CC(R)S(O) 2 OC H2 (R = C6H5). One member of this class (Mn(CO)5 CC(C 6 H 5 )S(O) 2 OC H2) was also obtained via oxidation of the corresponding vinyl-sultine, Mn(CO)5 CC(C 6 H 5 )S(O)OC H2). These sultone complexes exhibit much greater chemical and thermal stability than their sultine analogs.