Issue in Honor of Prof. Eusebio Juaristi ARKIVOC 2005 (vi) 153-161 ISSN 1424-6376 Page 153 © ARKAT USA, Inc An efficient synthesis of functionalized α-amino-phosphine oxides and -phosphonates by addition of aminoalcohols to 4-phosphorylated-1,2-diaza-1,3-butadienes Francisco Palacios,* Domitila Aparicio, Jesús M. de los Santos, Roberto Ignacio, and Yago López Departamento de Química Orgánica I, Facultad de Farmacia, Universidad del País Vasco, Apartado 450. 01080 Vitoria-Gasteiz, Spain E-mail: qoppagaf@vf.ehu.es Dedicated to Professor Eusebio Juaristi on the occasion of his 55 th anniversary (received 30 Mar 05; accepted 02 May 05; published on the web 04 May 05) Abstract Michael addition (1,4-addition) of achiral and chiral aminoalcohol derivatives to 1,2-diaza-1,3- butadienes derived from phosphine oxides and phosphonates gives functionalized α-amino- phosphine oxides and -phosphonates. Keywords: 1,2-Diaza-1,3-butadienes, functionalized α-amino-phosphine oxides and - phosphonates, Michael addition, phosphorylated hydrazones Introduction 1,2-Diaza-1,3-butadienes I (Figure 1) are widely used intermediates in organic synthesis 1,2 because they offer easy access to a broad range of heterocycles. Many of these heterodienes substituted on the terminal nitrogen (N-1) (I, R 1 = Me, Ar, ArSO 2 , COR, CO 2 R, CONR 2 ) 1a,3 and on the terminal carbon (C–4) (I, R 3 = Me, Br, Cl, COR, CO 2 R, CONR 2 , D-arabino- (CHOAc) 3 CH 2 OAc) 1a,2b,3,4 have been described. However, very little information about the behaviour of 1,2-diaza-1,3-butadienes II (Figure 1) containing phosphorus substituents at C–4 have been reported. 5 Furthermore, it is known that phosphorus substituents regulate important biological functions, 6 and the introduction of organophosphorus functionalities in simple synthons could be very interesting for the preparation of biologically active compounds.