A New Interpretation of the Reaction Pathway of Deprotonative Metalation with TMP−Zn-ate/TMEDA Complex [TMEDA·Na(μ-<i>^t</i>Bu)(μ-TMP)Zn(<i>^t</i>Bu)]

Density functional theory (DFT) calculations of possible reaction pathways and mechanisms for the deprotonation of benzene with Mulvey's reagent, TMEDA·Na(μ-R)(μ-TMP)Zn(R) (TMEDAN,N,N‘,N‘-tetramethylethylenediamine, R = alkyl, TMP = 2,2,6,6-tetramethylpiperidide) indicate that the deprotonation of benzene with Mulvey's reagent proceeds through a stepwise mechanism, not a one-step mechanism. In the first step, deprotonation involving the TMP ligand on the reagent is kinetically more favorable than that involving the alkyl ligand

Regio- and Chemoselective Silylmetalation of Functionalized Terminal Alkenes

A regio-/chemoselective silylmetalation of various functionalized alkenes based on the zinc silyl complex in the presence of a catalytic amount of copper cyanide was developed. Silylmetalation of alkenes, followed by electrophilic trapping, proved to be a powerful tool for the functionalization of the continuous carbon atoms of the alkenes. The resultant alkylsilanes can be converted smoothly into alcohols by oxidative cleavage of the carbon−silicon bond

Azulenocyanine: A New Family of Phthalocyanines with Intense Near-IR Absorption

Azulenocyanine: A New Family of Phthalocyanines with Intense Near-IR Absorptio

Cp₂TiCl₂-Catalyzed Regio- and Chemoselective One-Step Synthesis of γ-Substituted Allylsilanes from Terminal Alkenes Using Dianion-Type Zincate (SiSiNOL-Zn-ate)

A regio-/chemoselective silylation reaction of various functionalized terminal alkenes in the presence of titanocene dichloride, based on a newly designed dianion-type zincate, was developed. The present silylation of terminal alkenes is a powerful tool for the one-pot generation of regiocontrolled functionalized allysilanes, which are available for various transformation reactions, such as hydroxyalkylation, epoxidation, and hydroboration

Chemoselective Silylzincation of Functionalized Terminal Alkynes Using Dianion-Type Zincate (SiBNOL-Zn-ate): Regiocontrolled Synthesis of Vinylsilanes

A regio- and chemoselective silylzincation reaction of various functionalized alkynes was developed using a newly designed dianion-type zincate. Silylzincation of terminal alkynes, followed by electrophilic trapping, proved to be a powerful tool for the one-pot, regiocontrolled generation of trisubstituted functionalized alkenes. The functionalized vinylzincate intermediate also undergoes copper- and palladium-catalyzed C−C bond-forming reactions in high yields and with high regio- and chemoselectivities

Azulenocyanine: A New Family of Phthalocyanines with Intense Near-IR Absorption

Azulenocyanine: A New Family of Phthalocyanines with Intense Near-IR Absorptio

4<i>H</i>-1,2-Benzoxazines with Electron-Withdrawing Substituents on the Benzene Ring: Synthesis and Application as Potent Intermediates for Oxygen-Functionalized Aromatic Compounds

A new general method for synthesizing functionalized 4H-1,2-benzoxazine derivatives is described. Although 4H-1,2-benzoxazine is one of the fundamental structure of the oxazine group, no general synthetic method for the heterocycle has been established. We found that 3-methoxycarbonyl-4H-1,2-benzoxazine was obtained in good yield when methyl 2-nitro-3-phenylpropionate was treated with an excess amount of trifluoromethanesulfonic acid. This methodology was also applicable for the synthesis of 4H-1,2-benzoxazine rings functionalized with various electron-withdrawing substituents on the benzene ring. Furthermore, we also show that the resulting 4H-1,2-benzoxazines can be used as precursors of functionalized o-quinone methides and multisubstituted phenols. This type of heterocycle can be a potent intermediate to oxygen-fuctionalized aromatic compounds

Stannyl-Lithium: A Facile and Efficient Synthesis Facilitating Further Applications

We have developed a highly efficient, practical, polycyclic aromatic hydrocarbon (PAH)-catalyzed synthesis of stannyl lithium (Sn-Li), in which the tin resource (stannyl chloride or distannyl) is rapidly and quantitatively transformed into Sn-Li reagent at room temperature without formation of any (toxic) byproducts. The resulting Sn-Li reagent can be stored at ambient temperature for months and shows high reactivity toward various substrates, with quantitative atom efficiency

Aryne Polymerization Enabling Straightforward Synthesis of Elusive Poly(<i>ortho</i>-arylene)s

Herein we present the first straightforward aryne polymerization that successively connects aromatic rings at their <i>ortho</i>-positions, <i>directly</i> giving poly­(<i>ortho</i>-phenylene)­s of up to ca. 100-mer size. The polymerization proceeds smoothly in a chain-growth fashion in the presence of a monovalent copper reagent. Direct synthesis of poly­(<i>ortho</i>-arylene)­s has been a “missing piece” of aromatic chemistry for a long time (although the discovery of arynes dates back to 1902), in contrast to the well-investigated <i>para</i>- and <i>meta</i>-linked polyarylenes. Our achievement reported here is expected to open up new areas of nanocarbon and materials science