Synthesis and Characterization of New Pyrospirophosphoranes Containing a P-O-P Bond by the Atherton-Todd Reaction

Abstract

The classical Atherton–Todd reaction has been successfully applied to the synthesis of pentacoordinate pyrospirophosphoranes containing a P‐O‐P bond under mild conditions. The absolute configurations of the products were confirmed by X‐ray diffraction analysis and spectroscopic identification. And 31P NMR chemical shifts of the products were correlated with stereochemistry. A possible mechanism for explaining the stereochemistry of the reaction was proposed, and it could well explain the results of the reactions of different pentacoordinate hydrospirophosphoranes.

Synthesis and Characterization of Alkoxy Spirophosphoranes Prepared from Hydrospirophosphoranes and Sodium Alcoholates

“…The data in Table showed that the ratio of products was about 1:1 in most cases, although the rear attack was always considered to be the electronically preferred route. It has been reported that the steric hindrance always plays an important role in the stereochemistry products of AA‐HSPs . Therefore, it was speculated that the rear attack and front attack might easily happen simultaneously no matter which AA‐HSP was used, because alkoxide anions had relatively small volume.…”

Chiral Hypervalent, Pentacoordinated Phosphoranes

“…It was found, upon optimization of the reaction conditions, that the spirophosphoranes 137a,b gave the pure diasteroisomer of pyrospirophosphoranes 142a,b whereas a mixture of diastereoisomers 141c-e and 143c-e were isolated if hydrospirophosphoranes 137c-e were used as substrates. Similarly, the spirophosphoranes 137a-e and 138a-e were used as substrates for the synthesis of pentacoordinate pyrospirophosphoranes containing a P-O-P bond 141-143 under modified Atherton-Todd conditions [116] (Scheme 59). It was found, upon optimization of the reaction conditions, that the spirophosphoranes 137a,b gave the pure diasteroisomer of pyrospirophosphoranes 142a,b whereas a mixture of diastereoisomers 141c-e and 143c-e were isolated if hydrospirophosphoranes 137c-e were used as substrates.…”

Synthesis, crystal structure and hydrolysis of novel isomeric cage (P–C/P–O)-phosphoranes on the basis of 4,4,5,5-tetramethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane and hexafluoroacetone

“…Therefore, the synthesis, structure and chemical transformations of phosphoranes have attracted considerable attention. [20][21][22][23][24][25][26][27] Among the diverse synthetic methods for the preparation of phosphoranes, several general approaches based on the addition reactions of P(III)-derivatives to unsaturated systems, various reactions of tetracoordinated phosphorus and substitution reactions at P(V) 28,29 should be noted.…”

“…J HC 15,17 CC 13 ¼ 7.5 Hz, 2 J HC 3 C 13 ¼ 5.5 Hz, 3 J HOCC 13 ¼ 1.3 Hz, C 13 ), 135.36 (br. t (s),3 J HC 21,23 CC 19 ¼ 7.4 Hz, C19 ), 134.27 (dt (s), 1 J HC22 ¼ 162.9 Hz,3 J HC 20,24 CC 22 ¼ 7.7 Hz, C22 ), 129.86 (ddddd (s), 1 J HC20,24 ¼ 161.3 Hz,3 J HC 24,20 CC 20,24 ¼ 7.6 Hz,3 J HC 22 CC 20,24 ¼ 7.6 Hz, 2 J HC 21,23 C 20,24 ¼ 1.7 Hz,4 J HC 4 CCC 20,24 ¼ 1.3 Hz, C20,24 ), 129.52 (br. dm (s),1 J HC 15,17 ¼ 161.5-161.8 Hz, 3 J HC 15,17 CC 17,15 ¼ 6.0-7.0 Hz, C 15,17 ), 129.41 (dd (s), 1 J HC 21,23 ¼ 161.7 Hz, 3 J HC 23,21 CC 21,23 ¼ 7.6 Hz, C 21,23 ), 128.84 (dtd (s), 1 J HC 16 ¼ 161.0 Hz, 3 J HC 14,18 CC 16 ¼ 7.6 Hz, 5 J HC 3 CCCC 16 ¼ 1.1 Hz, C 16 ), 128.44 (dm (s), 1 J HC14,18 ¼ 162.4 Hz,3 J HC 18,14 CC 14,18 ¼ 6.5-7.5 Hz, 3 J HC 16 CC 14,18 ¼ 6.5-7.5 Hz, 3 J HC 3 CC 14,18 ¼ 4.5 Hz, C14,18 ), 76.94 (dt (s), 1 J HC 3 ¼ 146.8 Hz, 3 J HC 14,18 CC 3 ¼ 4.0 Hz, C 3 ) 13.…”