Hydroboration. 85. Synthesis and hydroboration of (-)-2-phenylapopinene. Comparison of mono(2-phenylapoisopinocampheyl)borane with its 2-methyl and 2-ethyl analogs for the chiral hydroboration of representative alkenes

Brown, Herbert C.; Weissman, Steven A.; Perumal, Paramasivan T.; Dhokte, Ulhas P.

doi:10.1021/jo00291a021

Cited by 52 publications

(55 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The trisylhydrazone 1 [5] of (1R,5S)-(+)-nopinone, which is available through ozonolysis of (À)-b-pinene ($80%) [6], was treated with 2.2 equiv. of sec-butyllithium in THF at À78°C under the standard Shapiro reaction condition [7].…”

Section: Resultsmentioning

confidence: 99%

“…85, 153.04, 151.39, 131.67, 123.75, 51.24, 40.58, 40.30, 34.27, 29.94, 27.36, 25.66, 24.97, 24.89, 23.69, 23.65, 22.27, 21.95, 19. ,9.15;N,6.69;S,7.66. Found: C,68.89;H,9.10;N,6.64; S, 7.65%.…”

Section: Preparation Of (1r5s)-nopinone Trisylhydrazone (1)mentioning

confidence: 99%

“…Found: C,86.19;H,9.15%. 3.5. Preparation of (1R,3R,6R,8R)- 1,2,3,4,5,5a,6,2,7,3:6, A solution of the alcohol 2 (2.70 g, 9.91 mmol) in THF (250 mL) was treated with concentrated sulfuric acid (0.03 mL, 0.56 mmol) and the resulting mixture was stirred at room temperature for 1 h, after which the reaction mixture was quenched with aqueous 1 N sodium hydroxide solution. The resulting mixture was extracted with n-hexane.…”

Section: Preparation Of Bis[(1r5s)-66-dimethylbicyclo [311]hept-2mentioning

confidence: 99%

“…13 C NMR (75.5 MHz, C 6 D 6 ) (a mixture of diastereomers) : d 151.99, 142.00, 137.42, 136.92, 129.32, 125.86, 123.31, 121.44, 62.38, 56.52, 44.35, 44.01, 43.93, 43.37, 43.06, 42.71, 40.73, 40.52, 37.10, 32.48, 32.31, 31.07, 29.13, 28.82, 27.12, 27.00, 26.79, 26.66, 26.60, 21.91, 21.82, 19.94 3.6. Preparation of (1R,3R,6R,8R) 2,3,4,5,6,7,2,7,3:6, A solution of the 3°alcohol 3 (1.54 g, 4.42 mmol) in dry diethyl ether (90 mL) was treated with boron trifluoride diethyl etherate (1.09 mL, 8.84 mmol) at 0°C. The reaction mixture was stirred for 5 h at this temperature.…”

Section: Preparation Of Bis[(1r5s)-66-dimethylbicyclo [311]hept-2mentioning

confidence: 99%

See 3 more Smart Citations

Synthesis of chiral highly hindered cyclopentadienylruthenium compounds

Kang

Lim

Ahn

et al. 2008

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Section: Preparation Of (1r5s)-nopinone Trisylhydrazone (1)mentioning

confidence: 99%

Section: Preparation Of Bis[(1r5s)-66-dimethylbicyclo [311]hept-2mentioning

confidence: 99%

Section: Preparation Of Bis[(1r5s)-66-dimethylbicyclo [311]hept-2mentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of chiral highly hindered cyclopentadienylruthenium compounds

Kang

Lim

Ahn

et al. 2008

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

“…The conversion of 6 to 7 by an alternate method would be advantageous. A recent report accomplishes the conversion in reasonable yield by osmate dihydroxylation followed by oxidative cleavage (51,52 Keto ester 8 was treated with phenylselenenyl chloride pyridine complex (54) in dichloromethane. The resulting selenide was oxidized with aqueous hydrogen peroxide to give the required enone ester 5 in 88% yield (65% overall from P-pinene).…”

Section: Introductionmentioning

confidence: 99%

Facial selective Diels–Alder reactions of (1R,5R)-(+)-3-carbomethoxy-6,6-dimethylbicyclo[3.1.1]hept-3-en2-one. Unusual ketalization–fragmentation reaction of adducts

Liu¹,

Chew²,

Browne³

et al. 1994

Can. J. Chem.

View full text Add to dashboard Cite

The stereofacially differentiated enone ester 5 has been used to study the effects of steric influence on the Diels-Alder reaction. In general, under Lewis acid catalysis, 5 adds to dienes at low to ambient temperatures in a reasonable rate. Yields of predictable chiral adducts are moderate with the unexpected exception of zinc chloride catalyzed reactions, which provide good to high yields. In all cases only products of addition to the Si face of general type 21 were observed. The regiochemistry of the adducts is exclusively that predicted by the ortho and para rules. The stereochemistry shows a high selectivity in favor of ester-endo transition state products. Rationales for the observed stereoselectivities are discussed. The fragmentation of adducts of 5, in particular keto ester 9, has been briefly examined. Olefins 30 and 46 derived from 9 have been converted to ring-opened cadinane skeletons 31 and 47, respectively, by conditions we have previously reported. In an entirely new and unexpected reaction, simultaneous ketalization and fragmentation of the cyclobutane ring of ketones derived from 9 gave ring-opened ketals 34 + 35 (from 29), 36 + 37 (from 9), 39 (from 38) and 42 + 43 (from 40).HSING-JANG LIU, SEW YEU CHEW, ERIC N.C. BROWNE et JEUNG BEA KIM. Can. J. Chem. 72, 1193Chem. 72, (1994.On a utilisC 1'Cnone ester 5 stCrCofacialement diffCrenciC pour Ctudier les effets stCriques sur la rCaction de Diels-Alder. En gCnCral, dans des conditions de catalyse acide de Lewis, le composC 5 s'additionne aux dibnes a des vitesses raisonnables, des tempkratures ne dCpassant pas la tempkrature ambiante. Les rendements des adduits chiraux attendus sont modCrCs, a l'exception notable des rkactions catalysCes par le chlorure de zinc qui donnent des rendements allant de bons 5 excellents. Dans tous les cas, on n'observe que les produits d'addition sur la face Si, de type gCnCral21. La rtgiochimie des produits est exclusivement celle que l'on peut prCdire sur la base des rbgles ortho etpara. La stCrCochimie prksente une grande sClectivitC pour les produits formCs par le biais de 1'Ctat de transition endo de l'ester. On a examink bribvement la fragmentation des adduits du produit 5, en particulier le cCto ester 9. Utilisant des conditions rapportCes antkrieurement, on a transform6 les olkfines 30 et 46, provenant du produit 9, en squelettes des cadinanes 2 cycle ouvert 31 et 47 respectivement. Par une rCaction aussi nouvelle qu'inattendue, une cktalisation et une fragmentation simultanCe du noyau cyclobutane des cCtones dCrivCs du produit 9 ont fourni les cCtals a cycles ouverts 34 + 35 (ii partir de 29), 36 + 37 (ii partir de 9), 39 (a partir de 38) et 42 + 43 (a partir de 40).[Traduit par la RCdaction]

show abstract

Hydroboration

Zaidlewicz

2000

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

The hydroboration reaction and transformations of its organoborane products are described. The mechanism and the chemo‐, regio‐, and stereoselectivity of the hydroboration reaction are presented, as well as the synthesis and characteristics of the most common hydroborating agents. Transformations of organoboranes may involve carbon‐hetero atom bond formation and lead to stereoselective synthesis of organic halides, amines, aziridines, sulfur, selenium, and mercury compounds. Hydroboration‐protonolysis is a nonocatalytic method of cis‐hydrogenation of multiple bonds. Hydroboration‐oxidation is a standard method for cis‐anti‐Markovnikov hydroxylation of multiple bonds. Carbon‐carbon bond formation can be accomplished by transformation of organoboranes through coupling of groups attached to boron, cross‐coupling of organoboranes with organic halides, organoborate rearrangements providing access to alkynes, ( E )‐ and ( Z )‐alkenes, ( E,E )‐, ( E,Z )‐, ( Z,Z )‐dienes, and enynes. Single‐carbon insertion reactions include carbonylation, cyanidation, and the DCME and related reactions. Other reactions include α‐ and β‐alkylation of carbonyl compounds, the addition of alkynyl, alkenyl, and allylic boranes to aldehydes, leading to proparylic alcohols and stereodefined allylic and homoallylic alcohols, boron‐stabilized carbanions, the boron Wittig reaction, and concerted reactions of allylic and vinylic boranes. Contrathermodynamic isomerization of olefins is discussed. The synthesis of boron‐containing polymers and of isotopically labeled compounds is covered. Asymmetric synthesis via chiral organoboranes is covered in detail.

show abstract

Hydroboration. 85. Synthesis and hydroboration of (-)-2-phenylapopinene. Comparison of mono(2-phenylapoisopinocampheyl)borane with its 2-methyl and 2-ethyl analogs for the chiral hydroboration of representative alkenes

Cited by 52 publications

References 0 publications

Synthesis of chiral highly hindered cyclopentadienylruthenium compounds

Synthesis of chiral highly hindered cyclopentadienylruthenium compounds

Facial selective Diels–Alder reactions of (1R,5R)-(+)-3-carbomethoxy-6,6-dimethylbicyclo[3.1.1]hept-3-en2-one. Unusual ketalization–fragmentation reaction of adducts

Hydroboration

Contact Info

Product

Resources

About