本文描述了杂芳烃的环状π-延伸(APEX)反应。使用二甲基二苯并甲硅烷作为π扩展剂的包含阳离子钯物种和邻氯甲腈的催化体系使苯并[ b ]噻吩的π系统得以扩展。π-扩展的二苯并呋喃和咔唑也可以分别从二甲基呋喃和锗的π-扩展剂分别从苯并呋喃和N-甲苯磺酰基吲哚得到。机理研究表明,两种可能的反应途径涉及基于碳链的苯并噻吩的双CH芳基化反应或正式的环加成/氧化级联反应。
Rhodium-Catalyzed Dehydrogenative Germylation of C–H Bonds: New Entry to Unsymmetrically Functionalized 9-Germafluorenes
摘要:
Rhodium-catalyzed dehydrogenative germylation leading to unsymmetrically functionalized 9-germafluorenes via GeH and CH bond activation is described. Despite the significant achievements made in dehydrogenative functionalization of CH bonds, only a limited number of examples with the fourth-row atomH bonds have been reported. The current method enabled the synthesis of various 9-germafluorene derivatives, including tetracyclic as well as donoracceptor substituted germoles, which may be useful for electronic device applications.
A new mode of aromatic metamorphosis has been developed, which allows thiophenes and their benzo‐fused derivatives to be converted to a variety of exotic heteroles. This transformation involves 1) the efficient generation of key 1,4‐dianions by means of desulfurative dilithiation with lithium powder and 2) the subsequent trapping of the dianions with heteroatom electrophiles in a one‐pot manner. Via
Rhodium-Catalyzed Silylative and Germylative Cyclization with Dehydrogenation Leading to 9-Sila- and 9-Germafluorenes: A Combined Experimental and Computational Mechanistic Study
rate constant of dehydrogenative germylation was greater than that of dehydrogenative silylation. Competitive reactions in the presence of 3,3‐dimethyl‐1‐butene indicated that the ratio of dehydrogenative metalation and hydrometalation was affected by reaction temperature when a hydrosilane or hydrogermane precursor was used. Further mechanistic insights of oxidant‐free dehydrogenative silylation, including
Rhodium-catalyzed dehydrogenative germylation leading to unsymmetrically functionalized 9-germafluorenes via GeH and CH bond activation is described. Despite the significant achievements made in dehydrogenative functionalization of CH bonds, only a limited number of examples with the fourth-row atomH bonds have been reported. The current method enabled the synthesis of various 9-germafluorene derivatives, including tetracyclic as well as donoracceptor substituted germoles, which may be useful for electronic device applications.