Aromatic amines and (hetero)arenes, such as indoles and pyrroles, are regioselectively sulfinylated under mild aerobic conditions using nitrosoarenes as a redox-catalyst. The nitrosoarene is involved in the electron transfer process with arenes to generate a crucial arene radical cation intermediate for C-H sulfinylation. The present methodology requires no directing group, can be scaled up easily
<i>Meta</i>- and <i>Para</i>-Difunctionalization of Arenes via a Sulfoxide−Magnesium Exchange Reaction
作者:Christian B. Rauhut、Laurin Melzig、Paul Knochel
DOI:10.1021/ol801431z
日期:2008.9.1
The aryl sulfoxide moiety (ArSO) allows an expedient two-step meta-, para-difunctionalization of readily available diarylsulfoxides. In the first step, the sulfoxide plays the role of a directing metalation group. In the second step, triggered by i-PrMgCl x LiCl, it becomes a leaving group and undergoes a regioselective sulfoxide-magnesiumexchange.
芳基亚砜部分(ArSO)可以方便地进行易得的二芳基亚砜的两步间,对二官能化。在第一步中,亚砜起着直接金属化基团的作用。在第二步中,由i-PrMgCl x LiCl触发,它成为一个离去基团,并进行区域选择性的亚砜-镁交换。
<i>Meta</i>-
and <i>Para</i>-Difunctionalization of Arenes
via an <i>Ortho</i>-Magnesiation and a Subsequent
Sulfoxide-Magnesium Exchange
作者:Laurin Melzig、Christian Rauhut、Paul Knochel
DOI:10.1055/s-0028-1087984
日期:——
Highly functionalized 1,2,4-trisubstituted arenes can be prepared on large scale by a two-step sequence, triggered by an aryl sulfoxide group. In the first step, the sulfoxide moiety acts as a metalation directing group, allowing a smooth magnesiation with tmpMgCl˙LiCl. After a quenching reaction with an electrophile, the resulting sulfoxide is converted with i-PrMgCl˙LiCl into a second magnesium
Methyl Sulfinates as Electrophiles in Friedel–Crafts Reactions. Synthesis of Aryl Sulfoxides
作者:Francisco Yuste、Angélica Hernández Linares、Virginia M. Mastranzo、Benjamín Ortiz、Rubén Sánchez-Obregón、Alberto Fraile、José Luis García Ruano
DOI:10.1021/jo2006335
日期:2011.6.3
The Friedel-Crafts reaction of methyl alkyl-and arylsulfinates with aromatic systems, activated by one or more electron-donating substituents (OH, OMe, NFIR, NR2), provides alkyl aryl and diaryl sulfoxides under mild conditions and in moderate to good yields. The very high regioselectivity usually observed in these sulfinylation reactions is rationalized on the basis of a Wheland intermediate having a trigonal bypyramidal structure in which steric and electronic interactions are significant factors strongly destabilizing the attack to the ortho positions.
Difunctionalisation of Arenes and Heteroarenes by Directed Metallation and Sulfoxide–Magnesium Exchange
作者:Laurin Melzig、Christian B. Rauhut、Nikolaus Naredi‐Rainer、Paul Knochel
DOI:10.1002/chem.201003657
日期:2011.5.2
The aryl sulfoxide moiety allows an expedient two‐step difunctionalisation of readily available diaryl sulfoxides. Highly functionalised 1,2,4‐trisubstituted arenes and difunctionalised heteroarenes (furans, thiophenes, benzofurans and pyridines) were prepared in a two‐step sequence, triggered by an aryl sulfoxide group. In the first step, the sulfoxide moiety acts as a metallation‐directing group