Isolation and Characterization of Stable Alkylidenephosphines

Abstract

E and Z-P-α- (t-Butyldimethylsilyloxy)benzylidene(2,4 ,6-tri-t-butylphenyl)phosphines were isolated as stable compounds.

Reactions of sterically protected phosphaalkenes with some boron reagents

“…It is interesting to note that the product ratio was almost the same even if the reaction was conducted with (Z)-2 [13], indicating that the reaction is not stereospecific. The E-isomer reacted with 5 more sluggishly than the Z-isomer, indicating that the reaction site of (Z)-2 is more hindered than that of (E)-2, as has been determined by X-ray analyses [3,4], and thus the energy release during the reaction of (Z)-2 is smaller than that of (E)-2. Furthermore, if 3 [4,14] was used as a substrate, no reaction with 5 proceeded, suggesting that the bulkiness caused by the two phenyl groups within 5 is detrimental for the hydroboration reaction with 5.…”

“…When phosphaalkene 1 [8] was allowed to react with catecholborane (5) [9], hydroboration proceeded only in the presence of ClRh(PPh 3 ) 3 [10] as a catalyst at room temperature for 2 hours to give 6, as shown in Scheme 1. No reaction of 1 proceeded in the absence of the catalyst.…”

“…Sterically protected organophosphorus compounds are of current interest because of their unusual structures and reactivities [1]. By utilizing a sterically bulky substituent, such as the 2,4,6-tri-t-butylphenyl group (abbreviated to the Ar group), we have been successful in preparation and characterization of diphosphenes (R-P‫ס‬P-R) [2] and phosphaalkenes (R-P‫ס‬CϽ) [3,4]. Among various kinds of their reactivities, only a little is known on the reaction of such double bonds with boron reagents.…”

Attempted 1,3‐trimethylsilyl migration in Me3SiPSNR system

“…Moreover, the course of the reaction seems to be similar to that of the reaction between N-sulfinyl-2,4-di-tert-butyl-6-methylaniline and lithium (tert-butyl-dimethyl- By analogy with the reaction described in [ 41, 1 can be considered to be a phosphorus-containing 1,3-dipole 2, which undergoes intramolecular cyclization to yield thiaphosphaziridine 3, a reopening of the three-membered ring of which leads to the iminophosphine P-sulfide 4. Unlike the similar iminophosphine P-sulfide described by Yoshihji et al [4] that is stabilized by sterically large groups, the intermediate 4 is not sterically protected enough and undergoes dimerization. The dimer 4, as shown in the Scheme, is oxidized by excess N-sulfinyltert-butylamine to give a dimer of thioxo-N-t-butylimino(trimethylsi1oxy)phosphorane 5.…”

Chromium tricarbonyl complex of phosphaalkene: Crystal structure and electrochemistry of the Cr(CO)3 complex of PhC(H)PMes*, EPR and DFT studies of its radical anion

“…n-BuLi (FLUKA) was titrated before use according to the method of Chong [10]. Mes*PH 2 [11,12] and tricarbonyl [1,2,3,4,5,6-g-benzaldehyde]chromium [13,14] were synthesized following methods described in the literature. The synthesis of the 13 C-enriched compound was performed using 13 C-labelled benzaldehyde supplied by Cambridge Isotope Labs.…”