Solid-Phase Synthesis and Asymmetric Reactions of Polymer-Supported Highly Enantioenriched Allylsilanes

Suginome, Michinori; Iwanami, Taisuke; Ito, Yoshihiko

doi:10.1021/ja005865r

Cited by 29 publications

(12 citation statements)

References 13 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The synthetic utility of the method has been demonstrated by the synthesis of highly enantioenriched, functionalized allylsilanes including those supported on a polymer resin. [31,32] …”

Section: Resultsmentioning

confidence: 99%

Stereoselective Synthesis of Highly Enantioenriched (E)‐Allylsilanes by Palladium‐Catalyzed Intramolecular Bis‐Silylation: 1,3‐Chirality Transfer and Enantioenrichment via Dimer Formation

Suginome

Iwanami

Ohmori

et al. 2005

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

Highly enantioenriched (E)-allylsilanes have been synthesized from optically active allylic alcohols on the basis of Pd-catalyzed intramolecular bis-silylation followed by highly stereospecific Si-O elimination reactions. The method involves three steps: 1) O-disilanylation of the allylic alcohols with chlorodisilanes, 2) intramolecular bis-silylation in the presence of a 1,1,3,3-tetramethylbutyl isocyanide/[Pd(acac)2] (acac = acetylacetonate) catalyst at 110 degrees C, and 3) treatment of the reaction mixture with organolithium reagents. The overall transformation proceeds with nearly complete conservation of the enantiopurity of the starting allyl alcohols by transposition of the C=C bond. For instance, (R)-(E)-3-decen-2-ol (99.6-99.7 % ee) produced (S)-(E)-4-(organosilyl)-2-decene of 98.8-99.4 % ee for a variety of silyl groups, including Me3Si, Me2PhSi, tBuMe2Si, Et3Si, and iPr3Si. In the bis-silylation step, the initially formed trans-1,2-oxasiletanes immediately dimerize to stereoselectively give 1,5-dioxa-2,6-disilacyclooctanes, which are isolated in high yield by carrying out the reaction at 70 degrees C. The eight-membered ring compounds undergo thermal extrusion of (E)-allylsilanes in high yield at 110 degrees C, along with formation of 1,3-dioxa-2,5-disilacyclohexane derivatives. These in turn undergo a Peterson-type elimination by treatment with nucleophiles such as BuLi and PhLi to give the (E)-allylsilanes. All of the steps involved in the sequence proceed with extremely high stereoselectivity and stereospecificity, leading to almost complete 1,3-chirality transfer through the overall transformation. The dimerization step, which forms diastereomeric intermediates, allows the synthesis of a highly enantioenriched allylsilane (99.4 % ee) from an optically active allylic alcohol with lower enantiopurity (79.2 % ee) by enrichment of enantiopurity. A general method for the determination of the enantiomeric excesses of (E)-allylsilanes is also described in detail.

show abstract

“…The synthetic utility of the method has been demonstrated by the synthesis of highly enantioenriched, functionalized allylsilanes including those supported on a polymer resin. [31,32] …”

Section: Resultsmentioning

confidence: 99%

Stereoselective Synthesis of Highly Enantioenriched (E)‐Allylsilanes by Palladium‐Catalyzed Intramolecular Bis‐Silylation: 1,3‐Chirality Transfer and Enantioenrichment via Dimer Formation

Suginome

Iwanami

Ohmori

et al. 2005

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…By doing so the authors avoided a difficult work-up of boronic acids, which often tend to form oligo and polyanhydrides. Thus, starting from the (DEAM-PS)-bound 3-amino boronic acids (438), Ugi reactions yielding dipeptides such as (441) have been performed (Scheme 90).…”

Section: Scheme 90mentioning

confidence: 99%

“…Addition of aldehydes to chiral-support-bound allylsilanes [441] Chiral 1,3-dialkylallylsilanes are carbanion equivalents, which, upon Ti-mediated stereoselective reaction with aldehydes give allyl alcohols with an (E)-double bond in high enantio-and threo-selectivity. Suginome et al [441] began the synthesis of these silanes by reacting a support-bound silyl silylchloride with chiral 1,3-dialkyl alcohols.…”

Section: Scheme 129mentioning

confidence: 99%

“…Suginome et al [441] began the synthesis of these silanes by reacting a support-bound silyl silylchloride with chiral 1,3-dialkyl alcohols. The authors shifted the C=C double bond of their chiral allylic precursor, concomitant with stereoselective formation of a chiral center involving a carbonsilicon bond to the solid phase.…”

Section: Scheme 129mentioning

confidence: 99%

“…One interesting example is the traceless attachment of a chiral silane onto a polymeric support (Scheme 179). The latter can serve as a template for Lewis acid induced diastereoselective allylations [441].…”

Section: Stereoselective Alkylations On a Chiral Solid Phasementioning

confidence: 99%

See 2 more Smart Citations