A selective route to aryl-triphosphiranes and their titanocene-induced fragmentation

Abstract

Using titanocene synthon [Cp2Ti(Me3SiC2SiMe3)] the selective conversion of aryl-substituted triphosphiranes P3Ar3 into Cp2TiP2Ar2 complexes was achieved.

Aryl-substituted Triarsiranes: Synthesis and Reactivity

“…Figure 1,F 2.4388(8), 2.472(1), 2.502(1) Å]. [10] Complexes of titanium with arsenic ligands are rare, and titanium complexes with a [17] In [Cp 2 Ti(btmsa)]…”

“…The As−As distance in 4 [2.4440(3) Å] is in the range of complexes 3 and considerably longer then in free (AsTer) 2 [2.276(3) Å], [27] and thus more descriptive of an As−As single bond. The As−Ti−As angle [4 54.738 11 11, Ti1−As1−As2 62.632(13), Ti1−As2−As1 62.630 (17), Ti1−As1−C1 108.50 7, Ti1−As2−C25 109.36 7, As2−As1−C11 111.41 7, As1−As2−C23 107.93(5) 111.10 7.…”

Aryl-substituted Triarsiranes: Synthesis and Reactivity

“…[16] Recently we outlined a methodology for the selective synthesis of aryl substituted triphosphiranes (PAr) 3 (Ar = Mes = 2,4,6-Me 3 -C 6 H 2 ; Dip = 2,6-i Pr 2 -C 6 H 3 , Tip = 2,4,6-i Pr 3 -C 6 H 2 ) and their fragmentation was observed in the reaction with the masked titanocene [Cp 2 Ti(C 2 (SiMe 3 ) 2 ] to give titanocene diphosphene complexes selectively. [17] S4 In this context, we wanted to extend this concept to the analogous arsenic systems.…”

“…No reduction of 1 was observed when using Zn powder in THF, indicating that PMe 3 is the active reductant. [17] Using Mg turnings as a reductant, the full consumption of either 1a or 1b was detected, however, selective formation of 2 was not achieved. [Σr cov (As−As) = 2.42 Å], [20] but in line with the three crystallographically characterized cyclotriarsanes [cf.…”

Phospha-Wittig Reagents Rediscovered

“…(1); Mes Ter (2); 8 2,6-{2,4,6-iPr 3 C 6 H 2 }-C 6 H 3 , Tip Ter (3); 9 1,1,3,3,5,5,7,7-octaethyl-1,2,3,5, 6 ,7hexahydro-s-in dacen -4-yl, EIND 10 ) have been described in the literature. These are generally obtained by the combination of the respective dichlorophosphine Ar-PCl 2 with zinc powder and an excess of PMe 3 , whereby PMe 3 acts as the active reductant (with concomitant formation of Cl 2 PMe 3 ), 11,12 and stabilizing base. Using ArP=PMe 3 in the reaction with aldehydes (note ketones cannot be converted using this methodology)…”