Oligophosphan-Liganden, XXXIX. (1S,2S)-trans-Cyclopentan-1,2-diyl-bis(phosphan), C₅H₈(PH₂)₂, durch Reduktion eines diastereomerenreinen Cyclopentandiyl-bis(dioxaphospholans) / Oligophosphine Ligands, XXXIX. (1 S,2S)-trans-Cyclopentane-1,2-diyl-bis(phosphine), C₅H₈(PH₂)₂, by Reduction of a Diastereomerically Pure Cyclopentanediyl-bis(dioxaphospholane)

Abstract

The title compound (S,S)-2, has been obtained by reduction with Li[AlH4] of the cyclopentane- 1,2-diyl-bis(1′,3′,2′-dioxaphospholane) (1S ,2S)-trans-C5H8[P(OCH (CO2Pr-i)- (R) - )2]2, (S,S)-1, which itself was isolated in diastereomerically pure form (X-ray structure analysis) from the reaction between rac, trans-C5H8(PCl2)2 and (2R,3R)-(+)-diisopropyl tartrate. Cleavage of (S,.S)-1 withPCl3 yielded an unseparable mixture of (1S,2S)-trans-C5H8(PCl2)2 and (4R.5R) -ClP [OCH(CO2Pr-i)-]2.

1,8-Bis[(dimethoxy)phosphino]naphthalene: A New Bis-phosphonite Ligand with a Rigid C3-Backbone and Unexpected Reaction Chemistry

“…In synthetic organophosphorus chemistry, aromatic and some aliphatic bis-phosphonites and bis-phosphonate esters such as A [7], B [8], C [9], D [10,11] and E [12] (Fig. 1) are valuable starting materials for the preparation of primary bis-phosphines [11,13] which have been successfully used for the synthesis of chiral bis-phosphines, e. g. 1,2-bis(phospholano)benzenes such as the DuPHOS-(A') and PennPHOS ligands (A'') [14], 1,1'-bis(2,5-dialkylphospholano)ferrocenes D' [10], duthixantphospholane-type (C') [9] and other chiral and non-chiral ligands [15] (Fig.…”

Enantioselective Catalysis; 130: Optically Active Expanded Ligands Based on the trans-1,2-Substituted Cyclopentane Skeleton

“…The dioxaphospholane (S,S)-1 11 was hydrolyzed in hydrochloric acid leading to the free phosphinic acid (S,S)-2, which was isolated and characterized. In the second step (S,S)-2 was chlorinated by stirring in PCl 3 giving the desired bisphosphonous acid dichloride (S,S)-3 in 21% total yield.…”

“…10 The key step, the crystallization of a single diastereomer formed with (+)-diisopropyl tartrate (DIPT), had been published earlier. 11 We used it to develop an alternative route to the chiral dichlorophosphane (S,S)-3 compared to that described in Ref. 10 (Scheme 1).…”

“…The Rh/substrate ratio was 1:400 and the results are summarized in Table 4. The octaimine 17 with eight D-valinol groups afforded the highest enantioselectivity [23% ee, The following compounds were synthesized according to the literature: 1-bromo-2-(dimethoxymethyl)benzene (4), 23 11 1,2-bis(dichlorophosphanyl)benzene (7), 24,25 trans-1,2-bis(dichlorophosphanyl)cyclopentane (22). 11 BuLi was used as a 1.6 M solution in hexane (Merck).…”

P‐Modular Homochiral Bis(phosphanes) with 1,2‐Disubstituted Cyclopentane Backbones in Asymmetric Hydrogenation

“…As an important breakthrough in the resolution of the enantiomers of the bis(phosphonous dichloride) L Cl , we found that the cyclopentane‐1,2‐diyl[bis(1′,3′,2′‐dioxaphospholane] L tart resulting from the reaction of rac ‐ L Cl with (2 R ,3 R )‐(+)‐diisopropyl tartrate (Scheme ) could be crystallized from the isomeric mixture as a single (1 S ,2 S ,4′ R ,5′ R ) diastereomer, ( S , S )‐ L tart ‐( R , R ) 25. As expected, the (1 R ,2 R ,4′ S ,5′ S ) enantiomer, ( R , R )‐ L tart ‐( S , S ) , was isolated, isomerically pure, from a similar reaction employing (2 S ,3 S )‐(−)‐diisopropyl tartrate as the diol component 26a.…”