Photocatalytic stannylation of white phosphorus

Abstract

Organophosphorus compounds (OPCs) are highly important chemicals, finding numerous applications in both academia and industry. Herein we describe a simple photocatalytic method for the stannylation of white phosphorus (P4) using...

Hydrostannylation of Red Phosphorus: A Convenient Route to Monophosphines

“…The industrial and academic applications of these isolated products include flame retardants ( 5 and 10 ), [1b,18] Wittig reagents ( 7 ), and chemical precursors ( 9 ), [1b,19] among others. Significantly, the formation of 7 and 8 could be performed in the absence of base which contrasts with previous results where a base was necessary for functionalisation of the intermediate P−H bonds present in (Bu 3 Sn) x PH 3− x ( x =1 or 2), thus highlighting an additional advantage of instead proceeding via (Bu 3 Sn) 3 P only [5f] …”

“…It was possible to isolate product 4 from this one‐step reaction in excellent yield (86 %, see Scheme 3a and Section 2.2 in the Supporting Information). More significantly, it was confirmed that (Bu 3 Sn) 3 P ( 4 ) could also serve as an intermediate “P 3− ” synthon and be functionalised with suitable electrophiles in a similar fashion to the previous (Bu 3 Sn) x PH 3− x mixture [5f] . For example, treatment of crude (Bu 3 Sn) 3 P generated from P red directly with paraformaldehyde in ethanol followed by quenching with HCl furnished THPC ( 5 ) in excellent isolated yield (85 %, see Scheme 3b and Section 3.1 in the Supporting Information).…”

“…To attempt to mitigate this problem it was decided to investigate the selective conversion of P red into the fully stannylated phosphine (Bu 3 Sn) 3 P ( 4 ) as a single product, as an alternative to the more complex, PH 3 ‐containing mixture (Bu 3 Sn) x PH 3− x ( x =1–3) [5f] . We previously found that addition of Bu 3 SnOMe prior to the hydrostannylation of P 4 results in conversion of the initially formed P−H bonds into P−Sn bonds, and that this can be used to selectively prepare 4 in excellent yield [13] .…”

“…To attempt to mitigate this problem it was decided to investigate the selective conversion of P red into the fully stannylated phosphine (Bu 3 Sn) 3 P ( 4 ) as a single product, as an alternative to the more complex, PH 3 ‐containing mixture (Bu 3 Sn) x PH 3− x ( x =1–3). [5f] We previously found that addition of Bu 3 SnOMe prior to the hydrostannylation of P 4 results in conversion of the initially formed P−H bonds into P−Sn bonds, and that this can be used to selectively prepare 4 in excellent yield. [13] Satisfyingly, when the already‐optimised hydrostannylation of P red was repeated in the presence of Bu 3 SnOMe the desired product 4 was formed seemingly quantitatively, without the need for any further reaction modifications (for further details see Section 2.1 in the Supporting Information).…”

Direct synthesis of phosphorotrithioates from [TBA][P(SiCl3)2] and disulfides

“…The most common route involves the use of Cl 2 , through the highly toxic compound PCl 3 , which then reacts with corresponding nucleophilic reagents while releasing large amounts of hydrochloric acid, with much environmental contamination. 2 In recent years, several methods involving direct activation of white phosphorus for producing organophosphorus compounds have been gradually developed, including those involving (1) the formation of arylated phosphines (Ar 3 P) and related phosphonium salts (Ar 4 P + ), [3][4][5][6] (2) construction of novel complex organophosphorus compounds by obtaining stable aryl P 4 anion structures under the action of Lewis bases and acids, 7,8 (3) activation of P 4 with bilithium reagents to prepare phosphorylated cyclopentadienyl lithium salts and phosphorus-containing cyclic organometallic compounds, [9][10][11] etc. Owing to the potential dangers of direct conversions of P 4 to P 1 products, there is a strong desire to discover more environmentally friendly and safer inorganic phosphorus sources for the synthesis of various OPCs.…”