reaction of alkynes with 2-bromophenylboronic acids under nitrogen gives naphthalene derivatives, in which two molecules of alkynes are incorporated. A vinylrhodium complex similar to II can also be generated by a different route by employing 2-bromophenyl(trimethylsilyl)acetylene and arylboronic acids in the presence of Rh(I) complex as the catalyst, resulting in the formation of indenones. The reaction
Osmium-Catalyzed 7-endo Heterocyclization of Aromatic Alkynols into Benzoxepines
作者:Alejandro Varela-Fernández、Cristina García-Yebra、Jesús A. Varela、Miguel A. Esteruelas、Carlos Saá
DOI:10.1002/anie.201000455
日期:——
The wizard of Os: Regioselective osmium‐catalyzed 7‐endo heterocyclization of aromaticalkynols affords benzoxepines in good yields. The proposed catalytic cycle involves the key formation of osmium–vinylidene complexes via an alkynyl‐hydride–osmium(IV) complex from the starting alkynol.
Abstract A divergent intramolecular reaction of phosphine tethered alkyne in protic solvent was developed. This provided a novel and simple access to a large variety of (Z)-alkenylphosphine oxides and phospholane oxides. Our preliminary studies suggested that these divergent reactions are closely related to the reaction condition and molecular structure. A possible mechanism of C-P bond cleavage of
A novel reaction system for intramolecular addition of benzyl anions to alkynes was developed by utilizing the [1,2]-phospha-Brook rearrangement under Brønsted base catalysis. The present reaction is a rare example of a catalytic additionreaction of an unstabilized benzyl anion under Brønsted base catalysis.
Synthesis of Phenanthrene Derivatives by Intramolecular Cyclization Utilizing the [1,2]-Phospha-Brook Rearrangement Catalyzed by a Brønsted Base
作者:Azusa Kondoh、Takuma Aoki、Masahiro Terada
DOI:10.1002/chem.201501377
日期:2015.9.1
The synthesis of functionalized phenanthrene derivatives was achieved by intramolecular cyclization utilizing the [1,2]‐phospha‐Brook rearrangement under Brønsted base catalysis. Treatment of biaryl compounds having an α‐ketoester moiety and an alkyne moiety at the 2 and 2′ positions, respectively, with diisopropyl phosphite in the presence of a catalytic amount of phosphazene base P2‐tBu provides
功能化的菲衍生物的合成是通过在Brønsted碱催化下利用[1,2]-磷-布鲁克重排进行分子内环化来实现的。在催化量的磷腈碱P2 - t Bu存在下,用亚磷酸二异丙酯处理在2和2'位置分别具有α-酮酸酯部分和炔烃部分的联芳基化合物,可以得到9,10-二取代的菲衍生物。高产。该反应涉及通过乌珀隆过程生成酯烯酸酯,即将亚磷酸二异丙酯添加至酮部分,然后进行[1,2]-磷-布鲁克重排,将分子内添加至炔烃,以及[3] ,3]以连续方式重新排列烯丙基磷酸酯部分。