Synthesis of S-Alkyl Phosphinocarbodithioates with Switch between P(III) and P(V) Derivatives

Abstract

Compound 9 is the first example of carbodithioate ester with a P=Se group and for the first time a phosphinocarboditioate with a free phosphine function (compound 10) is described. Stabilization of the latter crucially depends on the steric protection by the t-Bu groups, since an analogous derivative with R = Ph is observable but too unstable for isolation. Compound 10 can be reversibly protonated to yield the [t-Bu2PHC(S)SCH(Me)Ph] + cation (10-H +), which was isolated as a BF4salt. A few interconversion processes resulting in the facile addition/removal or exchange of the X group in this family of compounds are also described. The phosphorus atom oxidation state and the nature of electron-withdrawing group have a significant impact on the spectral properties.

Well-Defined PIII-Terminated Polymers from Phosphorylated Carbodithioate RAFT Agents

“…Both 1 and 4 present a similar level of control, with only slightly different dispersities after 120 h of reaction. Contrary to the nBA polymerizations (see above), neither loss of color nor disappearance of the phosphine-borane peak were observed during St polymerizations, which lasted up to 120 h. Thus, the thermal stability of the BH3-CTA derivatives is in accordance with our previous observations 35 and the slow decomposition of the phosphinocarbodithioate end groups during the polymerization of nBA may result from a specific reactivity between the phosphinocarbodithioate functionality and nBA or the propagating radical, such as the reduction of the nBA ester function by borane.…”

“…34 We have recently reported the simple and effective gram-scale synthesis of various S-(1-phenylethyl)(di-tert-butylphosphorylated)carbodithioates with different substituents on phosphorus (1-3 in Figure 1), explored their spectral properties and described simple chemical transformations between members of the series. 35 In particular, we have obtained for the first time thiocarbonylthio compounds with phosphine-borane (1) or free phosphine (3) as Z groups.…”

“…The synthesis of the new CTAs 4 and 5 (Figure 1), containing an S-bonded 1methoxycarbonylethyl group (acrylate-type radical) as R0, was similar to that previously described for the 1-phenylethyl derivatives 1 and 3, using methyl 2-bromopropionate as electrophile in the alkylation step instead of 1-bromo-ethylbenzene (see Scheme 1 and experimental part). 35 Scheme 1. Synthesis of 4 and 5.…”

Isolable Diaminophosphide Boranes

“…The P−C (1.849(4) Å) and C−S (1.680(54), 1.687(4) Å) distances match those reported for zwitterionic triaminophosphonio dithioformates (R 2 N) 3 P + –CS 2 − (P−C 1.848(4), 1.849(2) Å; C−S 1.651(4) to 1.675(3) Å [27] ) and a cationic ester (R 2 N) 3 P + –CS 2 Me (P−C 1.852(5) Å [28] ). Even if a slightly longer distance has been observed for a neutral species (R 2 N) 2 P–CS 2 –P(NR 2 ) 2 containing a tri‐coordinate P atom (P−C 1.895(4) Å [29] ), our findings are in accord with the presumption that the P−C and C−S distances in the PCS 2 fragment are rather insensitive to the nature of the P substituents [30] …”

“…Even if as lightly longerd istance has been observedf or an eutrals pecies (R 2 N) 2 P-CS 2 -P(NR 2 ) 2 containing a tri-coordinate Pa tom (PÀC1 .895(4) [29] ), our findings are in accordw ith the presumption that the PÀCa nd CÀSd istances in the PCS 2 fragment are rather insensitivet ot he nature of the Ps ubstituents. [30]…”