Synthesis of pyrrolo[1,2-a]naphthyridines by Lewis acid mediated cycloisomerization

2017 ◽  
Vol 15 (15) ◽  
pp. 3216-3231 ◽  
Author(s):  
Anika Flader ◽  
Silvio Parpart ◽  
Peter Ehlers ◽  
Peter Langer
Keyword(s):  

Functionalized pyrrolo[1,2-a]naphthyridines were synthesized by application of PtCl2 and Bi(OTf)3 as simple Lewis acids in a cycloisomerization reaction.

2008 ◽  
Vol 61 (8) ◽  
pp. 610 ◽  
Author(s):  
Guozhi Fan ◽  
Hanjun Zhang ◽  
Siqing Cheng ◽  
Zhandong Ren ◽  
Zhijun Hu ◽  
...  

Palladium chloride anchored on polystyrene modified by 5-amino-1,10-phenanthroline was prepared and used as an efficient recoverable catalyst for Suzuki cross-coupling reactions. The heterogeneous catalysts can be easily separated from the reaction mixture and reused for five cycles without significant Pd leaching and loss of catalytic activity. Rate enhancement in the Suzuki reaction by Lewis acids was also studied.


2017 ◽  
Vol 53 (75) ◽  
pp. 10366-10369 ◽  
Author(s):  
Shaoyu Mai ◽  
Changqing Rao ◽  
Ming Chen ◽  
Jihu Su ◽  
Jiangfeng Du ◽  
...  

Novel catalytic systems consisting of cationic gold complexes, N-hydroxyphthalimide (NHPI), and transition-metal-based Lewis acids have been developed for the one-pot synthesis of functionalized oxazoles.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jens Rudlof ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel

Abstract Based on the previously described bifunctional Lewis acid with a functional distance of the boron functions of 4.918(2) Å, the development of a further bifunctional, boron-containing Lewis acid with a wider functional distance is demonstrated. Again, a stannylated precursor was used and the Lewis-acidic boron functions were introduced by means of tin-boron exchange. The general suitability of this class of compounds for the formation of host-guest-complexes is demonstrated by NMR experiments and by solid-state structures using pyridine and TMPD (N 1,N 1,N 4,N 4-tetramethylbenzene-1,4-diamine) as Lewis basic guests. The influence of traces of moisture on the boron-containing, bifunctional Lewis acids was investigated by the structure elucidation of a decomposition product.


RSC Advances ◽  
2020 ◽  
Vol 10 (37) ◽  
pp. 21974-21985
Author(s):  
Patricia Camargo Solórzano ◽  
María T. Baumgartner ◽  
Marcelo Puiatti ◽  
Liliana B. Jimenez

Cyclodehydrogenation reactions of 2-substituted binaphthyls induced by a Lewis acid. Synthesis and theoretical studies of the reaction mechanisms.


2019 ◽  
Vol 43 (34) ◽  
pp. 13630-13634 ◽  
Author(s):  
Guohong Wang ◽  
Min Li ◽  
Wenmin Pang ◽  
Min Chen ◽  
Chen Tan

The Lewis acid-base interaction between B(iii) Lewis acids and the pyridazine moiety reduced the electron density from the Ni center and in situ modulated the pyridazine-imine nickel catalyzed ethylene (co)polymerisation.


2002 ◽  
Vol 74 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Keiji Maruoka

The chemistry of bidentate Lewis acids belongs to an unexplored field of science, and so far has been only poorly studied. This paper illustrates the design of several bidentate Al and Ti Lewis acids, and their successful application to selective organic synthesis, particularly to asymmetric synthesis. For example, a new, chiral bidentate Ti(IV) complex is successfully designed by adding commercially available Ti(OPri)4 and (S)-binaphthol sequentially to 2,2'-bis(tritylamino)-4,4'-dichlorobenzophenone in CH2Cl2, and can be utilized for simultaneous coordination to aldehyde carbonyls, thereby allowing the precise enantioface discrimination of such carbonyls for a new catalytic, practical enantioselective allylation of aldehydes with allyltributyltin. This chiral bidentate Ti(IV) catalyst exhibits uniformly high asymmetric induction as well as high chemical yields for various aldehydes. The present enantioselective allylation is highly chemoselective in the presence of other carbonyl moieties.


2017 ◽  
Vol 8 (10) ◽  
pp. 7197-7202 ◽  
Author(s):  
Guo-Peng Wang ◽  
Meng-Qing Chen ◽  
Shou-Fei Zhu ◽  
Qi-Lin Zhou

The first enantioselective Nazarov cyclization of substrates with only one coordinating site and with proton-transfer as an enantioselective-determining step was realized by means of cooperative catalysis with a Lewis acid and a chiral Brønsted acid.


RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 25703-25712 ◽  
Author(s):  
Naganna Narra ◽  
Badari Narayana Prasad Rachapudi ◽  
Sahithya Phani Babu Vemulapalli ◽  
Padmaja V. Korlipara

Novel bio-based cyclic carbonates were synthesised from ricinoleic acid by intra molecular rearrangement of an epoxy carbonate ester with Lewis acids.


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