A Young Woman With Hypertonia, Severe Scoliosis, and Encephalopathy.

A 31-year-old woman was seen with contractures in her fingers and toes, carpal inversion, dysarthria, dysphagia, hypertonia, decreased tendon reflexes, absence of Babinski sign, and no psychiatric problems and significant global atrophy. What is your diagnosis?

An unusual alkylidyne homologation.

The reaction of [W([triple bond, length as m-dash]CH)Br(CO)2(dcpe)] (dcpe = 1,2-bis(dicyclohexylphosphino)ethane) with tBuLi and SiCl4 affords the trichlorosilyl ligated neopentylidyne complex [W([triple bond, length as m-dash]CtBu)(SiCl3)(CO)2(dcpe)]. This slowly reacts with H2O to afford [W([triple bond, length as m-dash]CCH2tBu)Cl3(dcpe)] and ultimately H2C[double bond, length as m-dash]CHtBu via an unprecedented alkylidyne homologation in which coordinated CO is the source of the additional carbon atom with potential relevance to the Fischer-Tropsch process.

Rearrangement of bis(alkylidynyl)phosphines to phospha-acyls.

A range of bis(alkylidynyl)phosphines RP{C[triple bond, length as m-dash]M(CO)2(Tp*)}2 (M = Mo, W; R = Cl, Ph, Cy; Tp* = hydrotris(dimethylpyrazolyl)borate) are obtained from the reactions of [M([triple bond, length as m-dash]CLi)(CO)2(Tp*)] with Cl2PR or alternatively via the palladium(0)-mediated reactions of [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] with RPH2 (R = Py, Cy). The complexes RP{C[triple bond, length as m-dash]W(CO)2(Tp*)}2 rearrange slowly (R = Cl) or on heating (R = Ph) to afford the isomeric phospha-acyls [W2(µ:η1-C;η2-C,P-CCPR)(CO)4(Tp*)2].