benzosiloles is accomplished by 2-fold metalation of benzo[b]thiophenes substituted at C3 with ortho-brominated aryl groups followed by electrophilic substitution with dichlorosilanes. The method relies on the innate acidity of the C(sp2)–H bond at C2 of benzo[b]thiophenes and the halogen–metal exchange of the proximal C(sp2)–Br bond. The related indole- and benzofuran-annulated systems are also accessible
各种噻吩稠合的苯并甲酚的直接组装是通过在C3处用邻溴化的芳基进行2倍苯并[ b ]噻吩的2倍金属化,然后用二氯硅烷进行亲电取代来实现的。该方法依赖于苯并[ b ]噻吩的C2处C(sp 2)-H键的固有酸度和近端C(sp 2)-Br键的卤素-金属交换。也可以使用相关的吲哚和苯并呋喃环化的系统,但是这些硅烷的化学稳定性较差。还包括噻吩稠合的苯并germol的例子。
Convergent Synthesis of Fluorene Derivatives by a Rhodium‐Catalyzed Stitching Reaction/Alkene Isomerization Sequence
作者:Masaki Nishida、Ryo Shintani
DOI:10.1002/chem.201901519
日期:2019.6.4
the synthesis of fluorenederivatives has been developed by devising a rhodium‐catalyzed stitching reaction/alkene isomerization sequence. The reactions proceed smoothly under mild conditions for a variety of substrate combinations, and extended π‐conjugation systems are also readily accessible by utilizing this synthetic method. Optical properties of the obtained fluorenederivatives have also been
on the benzene ring, as well as through the protonation or alkylation of the nitrogenatom on the pyridine ring. A catalytic asymmetric synthesis of silicon‐centered axially chiral spirocyclic derivatives has also been achieved with high enantioselectivity by using a newly modified MeO‐MOP (MeO‐MOP=2‐(diphenylphosphino)‐2′‐methoxy‐1,1′‐binaphthyl) derivative as the chiral ligand. These spirocyclic compounds