Synthesis of 2-Azabicyclo[3.3.1]nonanes

This review highlights advances in the synthesis of morphan compoundsfrom 1980 to the present day. 1 Introduction 2 Synthetic Approaches from Carbocyclic Compounds 2.1 Aminocyclization Processes Forming the C(1)-NBond 2.1.1 From Amino Alkenes 2.1.2 From Amino Ketones 2.1.3 By Amine Alkylation 2.1.4 By Amino Conjugate Addition upon Enones 2.2 Aminocyclization Processes Forming the N-C(3)Bond 2.3 Cyclization Processes Forming the C(3)-C(4) Bond 2.4 Cyclization Processes Forming the C(4)-C(5) Bond 2.4.1 Aldol Reactions 2.4.2 Piperidine Ring Closure by a Heck Reaction 2.4.3 Alkenylation of Enolates 2.4.4 Radical Cyclizations 2.4.5 Miscellaneous Approaches 3 Synthetic Approaches from Piperidine Derivatives 3.1 Cyclization upon Iminium Ions Forming the C(1)-C(8) Bond 3.2 Cyclization Processes Forming the C(5)-C(6) Bond 3.3 Cyclization Processes Forming the C(6)-C(7) Bond 4 Cascade Processes 5 Rearrangements 6 Synthesis of 5-Phenylmorphans 7 Conclusions