Oligosubstituted Pyrroles Directly from Substituted Methyl Isocyanides and Acetylenes
作者:Alexander V. Lygin、Oleg V. Larionov、Vadim S. Korotkov、Armin de Meijere
DOI:10.1002/chem.200801395
日期:2009.1
methyl isocyanides 1 onto the triple bond of electron‐deficient acetylenes 2 represents a direct and convenient approach to oligosubstituted pyrroles 3. The scope and limitations of this reaction (24 examples, 25–97 % yield) are reported along with an optimization of the reaction conditions and a rationalization of the mechanism. In addition, a related newly developed CuI‐mediated synthesis of 2,3‐disubstituted
Silver-Catalyzed Isocyanide-Alkyne Cycloaddition: A General and Practical Method to Oligosubstituted Pyrroles
作者:Jianquan Liu、Zhongxue Fang、Qian Zhang、Qun Liu、Xihe Bi
DOI:10.1002/anie.201302024
日期:2013.7.1
key: The transition‐metal‐catalyzed cycloaddition of isocyanides and unactivated terminal alkynes has been realized with Ag2CO3 as a unique and robust catalyst (see scheme). The protocol is highly efficient, allowing a broad range of terminal and internal alkynes to react under base‐ and ligand‐free conditions, generating synthetically useful oligosubstitutedpyrroles in high yields.
Ag 2 CO 3是关键:Ag 2 CO 3是一种独特而坚固的催化剂,已经实现了过渡金属催化的异氰酸酯和未活化的末端炔烃的环加成反应(参见方案)。该方案非常高效,可以使各种末端和内部炔烃在无碱和无配体的条件下反应,从而以高收率生成合成上有用的寡取代吡咯。
The synthesis of novel pyrrololactams and their boronate ester derivatives
作者:Ryan Greenwood、Kay Yeung
DOI:10.1016/j.tetlet.2016.11.047
日期:2016.12
Pyrrololactams are naturally occurring compounds possessing interesting biological activities. A new methodology to form novel pyrrololactam systems has been developed via a silver-catalysed cycloaddition followed by a lactamisation reaction. Pyrrololactams were then selectively functionalised using iridium-catalysed borylation conditions and subsequently derivatised in Suzuki cross-couplings.
A new generation of aprotic yet Brønsted acidic imidazolium salts: low toxicity, high recyclability and greatly improved activity
作者:Lauren Myles、Rohitkumar G. Gore、Nicholas Gathergood、Stephen J. Connon
DOI:10.1039/c3gc40975a
日期:——
Catalysts which have low antimicrobial toxicity and are aprotic, yet which can act as Brønsted acidic catalysts in the presence of protic additives have been developed. The catalysts are recyclable, considerably more active (i.e. can be used at 10–50 times lower loadings) and of broader scope than their antecedent generation.
addition/annulation cascade was developed for the first time, and used to produce 27 hitherto unreported ethylene-linked 1-naphthol-imidazole pairs with generally good yields and complete stereoselectivity. An Ag2O-catalyzed reaction of yne-allenone esters with tosylmethyl isocyanide proceeded efficiently, and provided a simple and convergent protocol for the synthesis of fullysubstituted (Z)-ethylenes