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Cyclopenta[b]-pyrrole-2-phosphine oxides 4a and -phosphonates 4b,c are generated by the addition of cyclic enolates derived from ethyl 2-oxo-cyclopentanecarboxylate 2 to phosphorated 2H-azirines 1. However, the addition of enolate derived from acyclic 2-oxo-butanoate 10 to 2H-azirine phosphine oxide 1 led to vinylogous N-acyl-a-aminoalkyl phosphine oxides 12, involving the carbonyl group and the Ca of the keto ester 10. Ring closure of vinylogous derivative 12 in the presence of base afforded pyrrole-2-phosphine oxide 11. The addition of enolates derived from indenone-carboxylate 15 to 2H-azirines 1 led to the formation of functionalized N-substituted 1H-benzo[d]azepine derivatives 17. [ABSTRACT FROM AUTHOR]

A simple and efficient stereoselective synthesis of fluorine containing β-aminophosphonates by reduction of β-enaminophosphonates is described. Reduction with sodium cyanborohydride in the presence of zinc chloride and the catalytic hydrogenation of β-enaminophosphonates gives β-aminophosphonates. β-Enaminophosphonates are also used as intermediates for the regioselective synthesis of fluoroalkyl- substituted pyridines. [ABSTRACT FROM AUTHOR]

A simple and efficient selective synthesis of 1H-pyrrole-2-phosphine oxides 3 and -phosphonates 7 by addition of enolates derived from acetyl acetates to 2H-azirinylphosphine oxide 1 and -phosphonate 6 is reported. Nucleophilic addition of enolates derived from diethyl malonate to 2H-azirines 1 and 6 led to the formation of functionalized 2-hydroxy-lH-pyrrole-5-phosphine oxide 9 and -phosphonate 10, while vinylogous a-aminoalkylphosphine oxides 14 and -phosphonate 15 may be obtained from azirines and the enolate derived from diethyl 2-phenylmalonate. Ring closure of vinylogous derivatives 14 and 15 in the presence of base led to the formation of l,5-dihydro-3-pyrrolin-2-ones containing a phosphine oxide 17 or a phosphonate group 18. [ABSTRACT FROM AUTHOR]

This review summarizes the synthesis of γ-lactam ring using multicomponent reactions. 1 Introduction 2 Pyrrolidin-2-ones 3 Pyrrolin-2-ones (Dihydro-2H-pyrrol-2-ones) 4 Final Remarks [ABSTRACT FROM AUTHOR]