Yoshinori Kondo

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTTMP−Zincate as Highly Chemoselective Base for Directed Ortho MetalationYoshinori Kondo, Manabu Shilai, Masanobu Uchiyama, and Takao SakamotoView Author Information Graduate School of Pharmaceutical Sciences Tohoku University Aobayama, Aoba-ku, Sendai 980-8578, Japan Cite this: J. Am. Chem. Soc. 1999, 121, 14, 3539–3540Publication Date (Web):March 25, 1999Publication History Received11 December 1998Published online25 March 1999Published inissue 1

Abstract In der organischen Synthesechemie werden Monometallspezies wie Organolithiumverbindungen seit langem für Deprotonierungsreaktionen genutzt. In den letzten Jahren ist mit den 'at‐Komplexen eine neue Klasse von Metallierungsreagentien hinzugetreten, die das Syntheserepertoire metallorganischer Spezies ergänzt. Dank eines frei wählbaren Metallzentrums (Magnesium, Zink oder Aluminium), frei wählbarer Liganden (in Art und Anzahl) und eines frei wählbaren sekundären Metallzentrums (eines Alka

Copper-catalysed oxidative hydroxylation of arylboronic acids was accomplished in water containing an amphiphilic surfactant, providing facile access to phenol derivatives.

Regioselective palladium-catalyzed monoarylation of azoles was achieved using iodobenzoate immobilized on an insoluble polymer support. The positional selectivity for the coupling reaction was dramatically influenced by the presence of CuI. No diarylation was observed in either case. Unsymmetrical diarylation was also obtained with the polymer support using sequential coupling reactions.

Indoles with oxygen-bearing substituents such as a methoxy or (triisopropylsilyl)oxy group at all of the positions of the benzene moiety were synthesized by cyclization of tert-butyl methoxy(or (triisopropylsilyl)oxy)-2-((trimethylsilyl)ethynyl)phenyl)carbamates with potassium tert-butoxide in tert-butyl alcohol. The (ethynylphenyl)carbamates were synthesized by the palladium-catalyzed reaction of (trimethylsilyl)acetylene and the corresponding (iodophenyl)carbamates, which were selectively synt

The use of t-Bu3P as a ligand dramatically improved the generality of the double carbonylation of aryl iodides, and Mo(CO)6 was also found to be effective as a CO source in the system.

An efficient coupling of terminal alkynes and CO(2) in the presence of alkyl halides can be achieved under ambient conditions using a copper/phosphine catalyst system, providing facile access to a variety of functionalised alkyl 2-alkynoates.

Abstract The addition of O‐ and N‐nucleophiles to alkynes catalyzed by a phosphazene base, t ‐Bu‐P4 base, was investigated. Alkynes were easily transformed to enol ethers and enamines in DMSO by the addition of nucleophiles. When phenylacetylene was reacted with diisopropylamine, a unique head‐to‐head dimerization of phenylacetylene was observed to give the enyne derivative. Terminal proton of phenylacetylene was also catalytically activated by t ‐Bu‐P4 base to generate the acetylide anion which

Sequential reaction of HTMP (= 2,2,6,6-tetramethylpiperidine) with nBuLi and Et2Zn affords unsolvated polymer chains of EtZn(micro-Et)(micro-TMP)Li 6. The scope of this reagent in directed ortho metalation (DoM) chemistry has been tested by its reaction with N,N-diisopropylnaphthamide in THF to give EtZn(micro-C10H6C(O)NiPr2-2)2Li.2THF 7. Data reveal that 6 has undergone reaction with 2 equiv of aromatic tertiary amide and imply that it exhibits dual alkyl/amido basicity. DFT calculations reveal

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHalogen-Zinc Exchange Reaction of Haloaromatics with Lithium TrimethylzincateYoshinori Kondo, Nobuo Takazawa, Chizuru Yamazaki, and Takao SakamotoCite this: J. Org. Chem. 1994, 59, 17, 4717–4718Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August 1994https://pubs.acs.org/doi/10.1021/jo00096a005https://doi.org/10.1021/jo00096a005research-articleACS PublicationsRequest reuse permissionsArticle Vi

The activation of Ar-Si bonds in aryltrimethylsilane was investigated using a catalytic amount of t-Bu-P4 base and selective functionalizations of aryltrimethylsilanes in the absence of strong electron withdrawing groups on the aromatic rings were accomplished.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTartrate-derived aryl aldehyde acetals in the asymmetric directed metalation of chromium tricarbonyl arene complexesYoshinori Kondo, James R. Green, and Jianwei HoCite this: J. Org. Chem. 1993, 58, 23, 6182–6189Publication Date (Print):November 1, 1993Publication History Published online1 May 2002Published inissue 1 November 1993https://pubs.acs.org/doi/10.1021/jo00075a008https://doi.org/10.1021/jo00075a008research-articleACS PublicationsRequest reuse

Y. Kondo, A. Yoshida and T. Sakamoto, J. Chem. Soc., Perkin Trans. 1, 1996, 2331 DOI: 10.1039/P19960002331

Rh(II)-catalyzed N-H insertion reaction of immobilized alpha-diazophosphonoacetate with 2-haloanilines followed by Horner-Emmons reaction gave immobilized enaminoesters, which were efficiently cyclized to indoles via intramolecular palladium catalyzed reaction on a polymer support.