末木 俊輔

A concise and direct cyanation of secondary and tertiary benzylic and allylic alcohols catalyzed by Brønsted acid has been developed using trimethylsilyl cyanide (TMSCN) as a cyanide source and 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) as a solvent. The present transition metal‐free catalytic process is operationally simple to perform under “open‐flask” conditions and it is applicable to the preparation of a number of α‐arylacetonitriles as well as late‐stage material transformations. The effectiveness of the present protocol was further demonstrated by the first enantioselective synthesis and determination of the absolute configuration of verimol F.

Divergent synthesis of multi-substituted phenanthrenes based on an internal redox reaction/ring expansion sequence was achieved.

We have developed a sequential hydride shift process involving a [1,8]-hydride shift. When cinnamylidene malonates having a biphenyl core were treated with 30 mol% Yb(OTf)3 and 10 mol% iPr2NEt, the desired sequential [1,8]-[1,5]-hydride shift process proceeded smoothly to afford synthetically challenging nine-membered carbocycle-fused piperidine derivatives in good chemical yields (up to 77%). Notably, the desired nine-membered carbocycles could not be obtained by a single [1,8]-hydride shift/cyclization process, suggesting that the employment of the sequential system is crucial to achieving the reaction. (Figure presented.).

<p>ホウ素アニオン含有N-ヘテロ環状カルベン（WCA-NHC）配位子を有するイミド配位バナジウム錯体，V（N-2,6-Me₂C₆H₃）Cl₂（WCA-NHC）（1），触媒によるエチレン重合およびノルボルネンとの共重合における触媒活性は，使用するAl助触媒の影響を強く受け，特にAlⁱBu₃助触媒存在下でメチルアルミノキサン（MAO）より高活性を示した。触媒溶液の⁵¹V NMRスペクトル測定およびESR測定，V K-Edge XANES測定より，MAOの存在下での触媒溶液では価数変化が見られないのに対し，AlⁱBu₃の存在下の触媒溶液ではNMRおよびESRスペクトルが観察されず，XANESスペクトルよりAlによる還元反応が進行している可能性が示唆された。したがって，この触媒反応で見られるAl助触媒の効果は，価数の異なる触媒活性種の生成に起因することが示唆された。</p>

アゼチジンは窒素原子を含む飽和四員環複素環式化合物であり，医薬品や天然物などの部分骨格中に認められる．しかし，一般にアゼチジンはその大きなひずみのために合成が困難であり，これまでに効率的な合成法が少なかった．今回Chenらは，Pd触媒による分子内C–Hアミノ化反応を利用したベンズアゼチジン類合成法の開発に成功したので，紹介したい．<br>なお，本稿は下記の文献に基づいて，その研究成果を紹介するものである.<br>1) He G. et al.，Nature Chem., 8, 1131-1136(2016).<br>2) He G. et al., J. Am. Chem. Soc., 134, 3–6 (2012).<br>3) Gary J. B., Sanford M. S. Organometallics， 30， 6143–6149(2011).<br>4) Nielsen M. C. et al., J. Am. Chem. Soc., 135, 1978–1985(2013).

The rhenium-catalyzed synthesis of 1,3-diiminoisoindolines and their related compounds from aromatic or heteroaromatic imidates and carbodiimides are reported via C-H bond activation. This reaction is the first example of a transition-metal-catalyzed insertion of carbodiimides into an aromatic or heteroaromatic C-H bond and a novel method for synthesizing 1,3-diiminoisoindolines and their related compounds. Unsymmetrical 1,3-diiminoisoindolines were easily obtained using this method. The reaction proceeded in good to excellent yield using a variety of substrates.

A manganese- and borane-mediated synthesis of isobenzofuranones from esters and oxiranes is developed. The reaction proceeded at aromatic, heteroaromatic, and olefinic C-H bonds with high functional group tolerance. This is the first example of a manganese-catalyzed C-H transformation using an oxygen-directing group. Triphenylborane played an important role in this reaction to cooperatively promote the annulation reaction. Kinetic isotope effect experiments revealed that C-H bond activation of the aromatic rings was the rate-determining step.

Dihydropyridines (DHPs) are one of the most important nitrogencontaining heterocycles which are widely recorginized in the scaffold of various biologically active compounds and natural products. DHPs are also utilized as medicines and useful building blocks for the complex molecules. On the other hand, some DHPs exhibit blue fluorescence in organic solvents and have potential to apply as functional materials. Based on the novel utility of DHPs in both medicinal chemistry and material sciences, development of efficient and robust synthetic methods for DHPs has been paid much attention and a large number of synthesis of DHPs have been reported. In this review chapter, we would like to summarize the recent progress in synthetic methodologies for construction of DHP scaffolds both in catalytic and in stoichiometric manners (particularly from 2000 to present), which are classified by the reaction patterns as 1) Multi-Component Coupling Reactions, 2) Pericyclic Reactions, 3) Regioselective Transformations of Pyridines, and 4) Miscellaneous.

© Georg Thieme Verlag Stuttgart New York Synthesis 2015. In this review, transition-metal-catalyzed or -mediated C-H transformations leading to the synthesis of organic functional materials, such as oligomers, polymers, and π-conjugated molecules, are summarized. 1 Introduction 2 Oligomers and Polymers 2.1 Synthesis of Oligomers and Polymers 2.2 Chemical Modification of Polymers 3 π-Conjugated Molecules 3.1 Indenes and Fluorenes 3.2 Acenes 3.3 Triphenylenes 3.4 Chemical Modification of Perylene Diimides 3.5 Nanographenes 3.6 Condensed Polycyclic π-Conjugated Molecules with Five-Membered Heteroaromatic Rings 3.7 π-Conjugated Molecules with Nitrogen-Containing Six-Membered Heteroaromatics 3.8 Porphyrins 3.9 Miscellaneous (π-Conjugated Molecules) 4 Miscellaneous (Excluding Polymers and π-Conjugated Molecules) 5 Outlook and Conclusions.

<p>We successfully developed rhodium-catalysed synthesis of multi-substituted silylindenes from 2 equivalents of aryl alkynes and 1 equivalent of hydrosilanes in moderate to good yields <italic>via</italic> C–H bond activation for the first time.</p>

By the reaction of amines with alkylborane reagents in the presence of a catalytic amount of copper(II) acetate Cu(OAc)(2) and di-tert-butyl peroxide, a cross-coupling reaction proceeded and alkylated amines were obtained in good to excellent yields. Phenols are also applicable for this reaction, and the corresponding alkyl aryl ethers were produced.