Comprehensive Strategies for the Synthesis of Isoquinolines: Progress Since 2008

Abstract

In the past decades, an enormous number of reports have been dedicated towards the synthesis of nitrogen containing heterocycles. This immense interest have emerged owing to their wide varieties of pharmacological activities. The present review focused on the synthesis of isoquinoline derivatives, a family of N-heterocycles showing a broad range of structural diversity, biological and pharmaceutical activities. The progress on their synthetic strategies using versatile approaches are discussed in details.

Synthesis of Isoquinolylselenocyanates and Quinolylselenocyanates via Electrophilic Selenocyanogen Cyclization Induced by Pseudohalogen (SeCN)2 Generated in situ

“…Recently, electrophilic cyclization has been a powerful method to build various carbocycles [13] and heterocycles, [14] which are conducted under mild conditions. [15] Hence, it would be an innovative strategy to construct selenocyanates through electrophilic cyclizations. Nevertheless, no examples of sequential tandem selenocyanogen cyclization to form selenocyanates have been reported until now.…”

Rhodium(iii)-catalyzed annulation of enamides with sulfoxonium ylides toward isoquinolines

“…Consequently, the alternative efficient synthetic methodology for isoquinolines is of great importance. 6 Traditional methods, including the famous Bischler–Napieralski, 7 Pictet–Gams 8 and Pictet–Spengler 9 reactions, are well-established. Most of these protocols suffer from harsh reaction conditions and environmental problems.…”

Microwave-Assisted Palladium-Catalyzed Reductive Cyclization/Ring-Opening/Aromatization Cascade of Oxazolidines to Isoquinolines

“…In addition, transition-metal-catalyzed C–H functionalization has been demonstrated as an atom- and step-economical process to construct 3,4-disubstituted or 3-substituted isoquinolines (Scheme c) . However, a general protocol for the introduction of a 4-substituent on the isoquinoline is lacking . Although 4-substituted isoquinolines can be produced by the cross-coupling of 4-bromoisoquinolines with organometallic reagents or dehydrogenation of N-heterocycles, both strategies suffer from a rather limited substrate scope.…”