γ-Allyl Phosphinoyl Phenyl Sulfone (GAPPS):  A Conjunctive Reagent for the Synthesis of EE, EZ, and ET 1,3-Dienes

Li, Xiaojin; Lantrip, Douglas A.; Fuchs, P. L.

doi:10.1021/ja0377596

Cited by 25 publications

(15 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…13 C{ 1 H} NMR (125 MHz, CDCl 3 ): δ 202.1, 57.4, 46.6, 25.8, 18.3, −5.4. The spectral data (provided in the Supporting Information) were consistent with a previous report …”

Section: Methodssupporting

confidence: 89%

Preparation of β²-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Liu

Gellman

2020

J. Org. Chem.

View full text Add to dashboard Cite

β-homologous amino acids (βhAAs) are a valuable class of build blocks for novel analogues of bioactive peptides. Thus, practical methods to synthesize enantiopure βhAAs are desirable. We report the application of a collective synthesis strategy to prepare protected β 2 -homologous amino acids with polar side chains. In this approach, a core structure is constructed via proline-catalyzed Mannich reaction and subsequently derivatized to furnish more than one protected β 2 -homologous amino acid with a proteinogenic side chain.

show abstract

“…13 C{ 1 H} NMR (125 MHz, CDCl 3 ): δ 202.1, 57.4, 46.6, 25.8, 18.3, −5.4. The spectral data (provided in the Supporting Information) were consistent with a previous report …”

Section: Methodssupporting

confidence: 89%

Preparation of β²-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Liu

Gellman

2020

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…Phosphonate 18a was prepared by Arbuzov reaction of tert-butyl-6-bromo-2,4-dimethylsorbate and then coupled with a functionalized butanal derivative (18b) to afford the E,E,E-triene ester 18c which, after functional group manipulation, was converted into aldehyde 18d. Subsequent reaction of 18d with a vinylsulfone derived phosphonate (18e) [37] delivered the desired pentaunsaturated ester 18f (Scheme 18). OCO Incednine is a macrolactam antibiotic that exhibits significant inhibitory activity against some anti-apoptotic oncoproteins [38].…”

Section: Synthesis Of Building Blocksmentioning

confidence: 99%

Recent Applications of the Horner-Wadsworth-Emmons Reaction to the Synthesis of Natural Products

Bisceglia¹,

Orelli

2012

COC

View full text Add to dashboard Cite

The Horner-Wadsworth-Emmons reaction has evolved in the last years as one of the most powerful and reliable method for stereocontrolled olefin synthesis. The reaction has become a widespread standard tool in natural products total syntheses, providing access to relatively simple as well as highly complex synthetic targets. In this work we present the most representative applications within the field of natural product synthesis from 2000 to the present year. The examples comprise the synthesis of macrocycles, 5 to 7 membered rings, lipids and related compounds, alkaloids and cyclic ethers. They were chosen from a large amount of literature reports and illustrate the use of the HWE reaction in the synthesis and elaboration of key intermediates and in the crucial assembly of highly functionalized synthetic precursors.

show abstract

“…[1][2][3] This is mainly due to their highly selectiver eactions with aw ide range of electrophiles at the a-position and the exceptional nucleofugacity of the allylic sulfonyl group in, for example, transition metal-mediated reactions with nucleophiles. [4] In stark contrasts tands the almost complete neglect of the aspects associated with the chirality of I [5] and II,i ncluding their enantioselective synthesis andc onfigurational stability. [6,7] In addition, knowledge of the structure of I and II is,w ith the exception of some particular lithiated bicyclica llylic a-sulfonyl carbanions, [8,9] rather limited.…”

Section: Introductionmentioning

confidence: 99%

Chiral Lithiated Allylic α‐Sulfonyl Carbanions: Experimental and Computational Study of Their Structure, Configurational Stability, and Enantioselective Synthesis

Gerhards

Griebel

Runsink

et al. 2015

Chemistry A European J

View full text Add to dashboard Cite

X-ray crystal structure analysis of the lithiated allylic α-sulfonyl carbanions [CH2 CHC(Me)SO2 Ph]Li⋅diglyme, [cC6 H8 SO2 tBu]Li⋅PMDETA and [cC7 H10 SO2 tBu]Li⋅PMDETA showed dimeric and monomeric CIPs, having nearly planar anionic C atoms, only OLi bonds, almost planar allylic units with strong CC bond length alternation and the s-trans conformation around C1C2. They adopt a C1S conformation, which is similar to the one generally found for alkyl and aryl substituted α-sulfonyl carbanions. Cryoscopy of [EtCHCHC(Et)SO2 tBu]Li in THF at 164 K revealed an equilibrium between monomers and dimers in a ratio of 83:17, which is similar to the one found by low temperature NMR spectroscopy. According to NMR spectroscopy the lone-pair orbital at C1 strongly interacts with the CC double bond. Low temperature (6) Li,(1) H NOE experiments of [EtCHCHC(Et)SO2 tBu]Li in THF point to an equilibrium between monomeric CIPs having only OLi bonds and CIPs having both OLi and C1Li bonds. Ab initio calculation of [MeCHCHC(Me)SO2 Me]Li⋅(Me2 O)2 gave three isomeric CIPs having the s-trans conformation and three isomeric CIPs having the s-cis conformation around the C1C2 bond. All s-trans isomers are more stable than the s-cis isomers. At all levels of theory the s-trans isomer having OLi and C1Li bonds is the most stable one followed by the isomer which has two OLi bonds. The allylic unit of the C,O,Li isomer shows strong bond length alternation and the C1 atom is in contrast to the O,Li isomer significantly pyramidalized. According to NBO analysis of the s-trans and s-cis isomers, the interaction of the lone pair at C1 with the π* orbital of the CC double bond is energetically much more favorable than that with the "empty" orbitals at the Li atom. The C1S and C1C2 conformations are determined by the stereoelectronic effects nC -σSR * interaction and allylic conjugation. (1) H DNMR spectroscopy of racemic [EtCHCHC(Et)SO2 tBu]Li, [iPrCHCHC(iPr)SO2 tBu]Li and [EtCHC(Me)C(Et)SO2 tBu]Li in [D8 ]THF gave estimated barriers of enantiomerization of ΔG(≠) =13.2 kcal mol(-1) (270 K), 14.2 kcal mol(-1) (291 K) and 14.2 kcal mol(-1) (295 K), respectively. Deprotonation of sulfone (R)-EtCHCHCH(Et)SO2 tBu (94 % ee) with nBuLi in THF at -105 °C occurred with a calculated enantioselectivity of 93 % ee and gave carbanion (M)-[EtCHCHC(Et)SO2 tBu]Li, the deuteration and alkylation of which with CF3 CO2 D and MeOCH2 I, respectively, proceeded with high enantioselectivities. Time-dependent deuteration of the enantioenriched carbanion (M)-[EtCHCHC(Et)SO2 tBu]Li in THF gave a racemization barrier of ΔG(≠) =12.5 kcal mol(-1) (168 K), which translates to a calculated half-time of racemization of t1/2 =12 min at -105 °C.

show abstract

γ-Allyl Phosphinoyl Phenyl Sulfone (GAPPS): A Conjunctive Reagent for the Synthesis of EE, EZ, and ET 1,3-Dienes

Cited by 25 publications

References 8 publications

Preparation of β²-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Preparation of β²-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Recent Applications of the Horner-Wadsworth-Emmons Reaction to the Synthesis of Natural Products

Chiral Lithiated Allylic α‐Sulfonyl Carbanions: Experimental and Computational Study of Their Structure, Configurational Stability, and Enantioselective Synthesis

Contact Info

Product

Resources

About

γ-Allyl Phosphinoyl Phenyl Sulfone (GAPPS): A Conjunctive Reagent for the Synthesis of EE, EZ, and ET 1,3-Dienes

Cited by 25 publications

References 8 publications

Preparation of β2-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Preparation of β2-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Recent Applications of the Horner-Wadsworth-Emmons Reaction to the Synthesis of Natural Products

Chiral Lithiated Allylic α‐Sulfonyl Carbanions: Experimental and Computational Study of Their Structure, Configurational Stability, and Enantioselective Synthesis

Contact Info

Product

Resources

About

Preparation of β²-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy

Preparation of β²-Homologous Amino Acids Bearing Polar Side Chains via a Collective Synthesis Strategy