8. Heck-Type Cyclization of Oxime Ethers: Stereoselective Carbon-Carbon Bond Formation with Aryl Halides To Produce Heterocyclic Oximes
Hiroaki Ohno, Akimasa Aso, Yoichi Kadoh, Nobutaka Fujii, Tetsuaki Tanaka Angewandte Chemie International Edition , 46, 6325-6328 (2007).
7. Radical Fixation of Functionalized Carbon Resources: α-sp3C-H Carbamoylation of Tertiary Amines with Aryl Isocyanates
Takehiko Yoshimitsu, Kenichi Matsuda, Hiroto Nagaoka, Koji Tsukamoto, Tetsuaki Tanaka, Org. Lett. , 9, 5115-5118 (2007).
Abstract:A new carbamoylation of tertiary amines is reported.
This rare C-H transformation features the direct generation of α-aminoalkyl
radicals from tertiary amines, followed by the addition of the resultant nucleophilic
radicals to isocyanates, enabling unique access to N,N-dialkylated amino acid derivatives.
The authors put forward a mechanistic proposal that is based on the isolation of borinamides
produced by capturing nitrogen radical intermediates with Et3B. The present transformation
provides a novel one-step process for producing mepivacaine, a clinically important local
anesthetic, from readily available materials.
6. A Stereocontrolled Construction of rel -(7S, 8S, 7'R, 8'S)-7,7'-Epoxylignan Skeleton
Maria Kitamura, Hiromi Hayashi, Masahiro Yano, Tetsuaki Tanaka, Naoyoshi Maezaki, Heterocycles, 71, 2669-2680 (2007).
5. Zipper-Mode Double C-H Activation: Palladium-Catalyzed Direct Construction of Highly-Fused Heterocyclic Systems
Hiroaki Ohno, Mutsumi Iuchi, Nobutaka Fujii, Tetsuaki Tanaka, Organic Letters, 9, 4813-4815 (2007).
4. Carbon-Carbon and Carbon-Hydrogen Bond Transformations Mediated by Highly Reactive Radicals and Their Application to the Synthesis of Bioactive Compounds
Takehiko Yoshimitsu, Hiroto Nagaoka, Tetsuaki Tanaka, J. Synth. Org. Chem., Jpn., 65(7), 665-676 (2007).
Abstract:Reactive free radicals have wide applications in organic synthesis due to their remarkable chemical properties that allow useful molecular transformations. The present review covers the author’s recent studies on the utilization of radical species in chemical synthesis of organic molecules: the first topic deals with two types of alkoxyl radicals (primary or tertiary) that selectively undergo dehydrogenation or β-scission to give rise to the key structural elements of (-)-CP-263,114, a ras-farnesyl transferase inhibitor. The second part of this review describes the development of new carbon-carbon bond forming reactions that proceed via the direct and selective abstraction of the hydrogen from the sp3C-H bond adjacent to oxygen or nitrogen. In this radical C-H bond transformation, triethylborane serves not only as a source of hydrogen abstractor but as an alkoxyl radical scavenger that enables the irreversible addition of carbon radicals to carbon-oxygen double bonds.
3. Synthesis of Fluorescent Solamin for Visualization of Cell Distribution
Naoyoshi Maezaki, Daisuke Urabe, Masahiro Yano, Hiroaki Tominaga, Takekuni Morioka, Naoto Kojima, Tetsuaki Tanaka, Heterocycles, 73, 159-164 (2007).
Abstract:Asymmetric synthesis of fluorescent solamin was accomplished by using
highly stereoselective asymmetric alkynylation and Williamson
etherification as the key steps, wherein the fluorescent acetogenin with
all functionality was firstly synthesized.
2. A Highly Regio- and Stereoselective Formation of Bicyclo[4.2.0]oct-5-ene Derivatives through Thermal Intramolecular [2 + 2] Cycloaddition of Allenes
Hiroaki Ohno, Tsuyoshi Mizutani, Yoichi Kadoh, Akimasa Aso, Kumiko Miyamura, Nobutaka Fujii, Tetsuaki Tanaka, J. Org. Chem. 72, 4378-4389 (2007).
1. フリーラジカルによる α-ヘテロ原子置換 sp3炭素―水素結合の新変換法の発見と進展
好光健彦, ファルマシア, 43, 219－223（2007）.