N-PHOSPHINONITRILIMINE AND N-PHOSPHONIONITRILIMINE - FROM NUCLEOPHILIC TO ELECTROPHILIC 1,3-DIPOLES

opropylamino)phosphino]-C-[bis(thioxophosphoranyl] nitrilimine (1) rea cts with electron-poor dipolarophiles such as maleimide, methyl vinyl ketone, and 1,4-naphthoquinone via HOMO(dipole)-controlled [2+3] cyclo additions, while N-[bis(diisopropylamino)(methyl)phosphonio]-C- is(dii sopropylamino)thioxophosphoranyl]nitrilimine (2a) reacts with electron -rich dipolarophiles such as norbornadiene and ethyl trans-pyrrolineac rylate via LUMO(dipole)-controlled [2+3] cycloadditions. Carbon disulf ide reacts with 1 via a formal [4+2] cycloaddition leading to phosphaz ene containing heterocycle 11 in 75% yield. Dipole 1 is cleaved by HCl , giving the corresponding (thioxophosphoranyl)diazomethane 15, while addition of HCl to 2a leads to hydrazonoyl chloride 16, in 70% isolate d yield. Hydrazone 17' (95%) and phosphazine 18 (80%) are obtained by a 1,3-addition of BuLi to 1 and PhOLi to 2a, respectively. Trimethylph osphine reacts with 2a by a phosphine-carbene coupling reaction, givin g the ylide 20 which is isolated in 75% yield.