Copper-mediated cross-coupling alcohols

The involvement of organocopper intermediates in various cross-coupling reactions carried out in the presence of Cu1 is often suggested, although in the majority of cases no experimental proof is provided, and the actual role of Cu1 may be different (Section 9.6.3.2.1). The potential of copper-mediated cross-coupling can be shown by the stereospecific reaction of 3-trimethylsilylallylic alcohols, which takes place via a prior transmetalation of Si to Cu (37).157... 

A convenient and efficient synthesis of 4-halo-2,5-dihydro-l,2-oxa-phosphole 2-oxides (254) through CuX2-mediated direct halocyclisation of diethyl 1,2-allenylphosphonates (253) has been described by Ma and Xin. Further Suzuki cross-coupling of the resultant chloro derivatives (254) with phenylboronic acid, has been also established (Scheme 90). ot-Amino allenephosphonates (258) have been easily prepared in two steps from protected amines (255), 3-bromopropargyl alcohols (257) and chlorophosphites. In the first step, a copper (II) catalysed coupling reaction of unprotected 1-bromopropargyl alcohols (256) and amines (256)... 

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