Michinori Suginome

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTransition-Metal-Catalyzed Additions of Silicon−Silicon and Silicon−Heteroatom Bonds to Unsaturated Organic MoleculesMichinori Suginome and Yoshihiko ItoView Author Information Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan Cite this: Chem. Rev. 2000, 100, 8, 3221–3256Publication Date (Web):July 20, 2000Publication History Received11 January 2000Published online20 July

Alkynylboration has been achieved in the reaction of alkynyl(pinacol)boranes with alkynes in the presence of nickel catalysts, giving cis-1-borylbut-1-en-3-yne derivatives. 1-Aryl-1-alkynes underwent the alkynylboration regioselectively with the selective introduction of the alkynyl groups at their 1-positions, where the aryl groups were attached. The boryl-substituted enynes were reacted with sp2 halides under the Suzuki-Miyaura coupling conditions, giving highly conjugated enynes in high yield

(Triorganosilyl)pinacolboranes were prepared by reaction of triorganosilyllithium reagents with pinacolborane or isopropoxypinacolborane in high yield. The reaction also is applicable to synthesis of 2-(triorganosilyl)-4,4,6-trimethyl-1,3,2-dioxaborinane. A new germylborane derivative was similarly prepared from the corresponding germyllithium.

Intramolecular addition of a boron-cyano bond across a carbon-carbon triple bond was achieved using palladium and nickel catalysts. Cyano(diisopropylamino)boryl homopropargyl ethers underwent regio- and stereoselective 5-exo cyclization, forming five-membered cyclic boryl ethers in high yields. The cyanoboration products thus obtained served as new precursors for the synthesis of highly substituted alpha,beta-unsaturated nitriles via transition-metal-catalyzed transformations.

Addition of the silicon–boron bond across carbon–carbon triple bonds, i.e. silaboration is most effectively catalysed by a palladium(0)–tert-alkyl isocyanide complex to give (Z)-1-boryl-2-silyl alkenes with high regio- and stereo-selectivity, which are useful for synthesis of stereodefined alkenylsilanes.

Highly versatile intermediates are formed through the Pd-catalyzed cyanoboration of alkynes, which proceeds in a cis fashion. When 1-aryl alkynes are used, the corresponding α,β-unsaturated β-boryl nitriles are obtained regioselectively in good yields with the cyano group α to the aryl group. Suzuki–Miyaura coupling of the products leads to highly substituted α,β-unsaturated nitriles (see scheme).

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPalladium- and Platinum-Catalyzed Silaboration of Methylenecyclopropanes through Selective Proximal or Distal C−C Bond CleavageMichinori Suginome, Takanori Matsuda, and Yoshihiko ItoView Author Information Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering Kyoto University, Kyoto 606-8501, Japan Cite this: J. Am. Chem. Soc. 2000, 122, 44, 11015–11016Publication Date (Web):October 21, 2000Publication History

Transition-metal-catalyzed carboborations, in which organic and boryl groups are introduced concomitantly to unsaturated organic molecules, have been developed. Direct carboborations, which proceed via activation of B-C bonds of cyanoboranes and alkynylboranes, and transmetalative carboborations, in which activation of B-Cl bonds is followed by transmetalation from organotin and organozirconium reagents, are overviewed. In addition, as representative results and mechanistic considerations, the s

Double insertion of alkynes into the Si−B bond of (dimethylphenylsilyl)pinacolborane proceeded in the presence of nickel(0) catalysts to give cis,cis-1-silyl-4-boryl-1,3-butadiene derivatives in a regio- and stereoselective manner. Involvement of (silyl)(2-boryl-1-alkylvinyl)nickel(II) intermediates in the silaborative dimerization reaction was suggested by the regiochemical preference as well as on the basis of reactions of the corresponding germylborane with alkynes in the presence of Ni, Pd,

Enantioenriched beta-borylallylsilanes were synthesized by palladium-catalyzed enantioface-selective addition of the silicon-boron bond to terminal allenes using a palladium catalyst possessing a chiral monodentate phosphine ligand. Use of a silylborane bearing a chiral auxiliary on the boron atom was beneficial to gain enantioface selectivities as high as 96% de.

Three-component coupling of bis(dialkylamino)chloroborane, alkynes and organozirconium reagents proceeded in the presence of palladium catalysts, leading to the formation of stereo-defined alkenylborane derivatives via cis-carboboration of carbon-carbon triple bonds.

A highly efficient majority-rules effect of poly(quinoxaline-2,3-diyl)s (PQXs) bearing 2-butoxymethyl chiral side chains at the 6- and 7-positions was established and attributed to large ΔG(h) values (0.22-0.41 kJ mol(-1)), which are defined as the energy difference between P- and M-helical conformations per chiral unit. A PQX copolymer prepared from a monomer derived from (R)-2-octanol (23% ee) and a monomer bearing a PPh2 group adopted a single-handed helical structure (>99%) and could be used

2-Boryl-1-silylalkanes form regioselectively upon addition of a BSi bond to the CC double bond of simple terminal alkenes in the presence of a (triphenylphosphane)platinum complex as catalyst [Eq. (1)]. At the BC bond, homologation by one C atom is possible.