A new, highly stereoselective reducing agent, potassium 9-(2,3-dimethyl-2-butoxy)-9-boratabicyclo[3.3.1]nonane

Brown, Herbert C.; Soon, Jin; Nazer, Behrooz

doi:10.1021/jo00185a067

Cited by 17 publications

(7 citation statements)

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“…The organic phase was extracted three times with 2 N KOH, washed three times with water, and dried over magnesium sulfate, and the solvent was removed. Chromatography on silica gel from ethyl acetate followed by recrystallization from ether/hexane yielded 12.3 g (62%) of 6: mp 116 °C; IR (KBr) x(C=0) 1640 cm"1; NMR (360 MHz, CDC13) 1.65 (quint, J = 6.5 Hz, 4 H, OCH2CH2Cíf2), 1-80 (quint, J = 6.5 Hz, 4 H, CH2CH2C1), 1.86 (quint, J « 6.5 Hz, 4 Hz, CH2CH20), 2.06 (s, 3 H, CH3CO), 2.1-2.3 (m, 4 H, NCH2CH2C), 2.21 (s, 12 H, aryl-CHs), 3.4-3.6 (m, 4 H, NCH2CH2C), 3.56 (t, J = 6.5 Hz, 4 H, CHjCl), 3.74 (t, J = 6.5 Hz, 4 H, OCH2), 6.82 (s, aryl-H); MS, mjz (relative intensity) 575 (100, M+). Anal.…”

Section: Methodsmentioning

confidence: 99%

“…Following the procedure described above for the synthesis of 6, 5.93 g (18.0 mmol) of 11 and 94.96 g (0.673 mol) of 1,5-dichloropentane afforded a crude product containing two major components with R¡ =0.4 and Rf =0.05 (Si02/EtOAc). Chromatography on silica gel from ethyl acetate and recrystallization from ether/hexane gave 4.87 g (50%) of dichloride 12 with the higher Rf value: mp 133 °C dec; IR (KBr) KN-H) 3260, KC=0) 1640 cm"1; NMR (360 MHz, CDC13) 1.28 (q, J =« 7.5 Hz, 4 H, OCH2CH2CH2), 1.5-1.65 (m, 8 H, OCH2CH2CH2CH2), 1.91 (s, 6 H, CH3CO), 3.37 (t, J c* 6.5 Hz, 4 H, CH2C1), 3.75-3.95 (m, 4 H, OCH2), 4.02 and 4.11 (AB part of AJBX, J = 15.0 and 5.4 Hz, 4 H, aryl-Cff2NH), 6.65 (s, br, X-part of ABX, 2 H, CH2NH), 6.85 (d, J = 8.2 Hz, 2 , 5.5'-H), 7.04 (d, J = 7.6 Hz, 2 H, 3,3'-H), 7.29 (t, J a* 8 Hz, 2 H, 4.4'-H); MS, m/z 536 (M+). Anal.…”

Section: Methodsmentioning

confidence: 99%

“…15: mp 77 °C (ether); NMR (500 MHz, CDC13) 1.1-1.2 (m, 4 H, OCH2CH2CH2), 1.35-1.6 (m, 8 H, OCH2CH2CH2CH2), 2.07 (s, 12 H, (C/f3)2NCH2), 2.14 (s, 12 H, aryl-CH3), 2.24 (s, 3 H, NCH3), 2.2-2.4 (m, 4 H, NCH2CH2C), 2. 4-2.6 (m, 4 H, NCH2CH2C), 2.93 and 2.95 (AB, J = 14.5 Hz, 4 H, N-CH2-aryl), 3.55-3.75 (m, 8 H, 0CH2CH2CH2CH2CH20), 6.47 (d, J = 8.0 Hz, 2 H, Bp-3,3'-H), 6.82 (s, 4 H, aryl-HDPM), 4 H,4',5,; MS, m/z (70 eV) (relative intensity) 775 (14, M+), 70 (100); m/z (16 eV) NMR (500 MHz, CDC13) 1.1-1.2 (m, 4 H, OCH2CH2CH2), 1. 4-1.6 (m, 8 H, OCH2Ctf2CH2CH2), 2.17 (s, 12 H, aryl-CH3), 2.24 (s, 3 H, NCH3), 2.30 (s, 3 H, NCH3), 2.S-2.6 (m, 8 H, NCH2CH2C), 3.02 and 3.36 (AX, J = 12.2 Hz, 4 H, MeN-CH2-Aryl), 3.55-3.8 (m, 8 H, 0CH2CH2CH2CH2Ctf20), 6.46 (d, J = 8.2 Hz, 2 H, DBA-2,10-H),43 6.85 (d, J = 7.3 Hz, 2 H, DBA-4,8-H), 6.90 (s, 4 H, aryl-HDPM), 7.09 (t, J =* 7.8 Hz, 2 H, DBA-3,9-H); MS, m/z (relative intensity) JV,lV,JV ',JV,.…”

Section: Methodsmentioning

confidence: 99%

“…4-2.6 (m, 4 H, NCH2CH2C), 2.93 and 2.95 (AB, J = 14.5 Hz, 4 H, N-CH2-aryl), 3.55-3.75 (m, 8 H, 0CH2CH2CH2CH2CH20), 6.47 (d, J = 8.0 Hz, 2 H, Bp-3,3'-H), 6.82 (s, 4 H, aryl-HDPM), 4 H,4',5,; MS, m/z (70 eV) (relative intensity) 775 (14, M+), 70 (100); m/z (16 eV) NMR (500 MHz, CDC13) 1.1-1.2 (m, 4 H, OCH2CH2CH2), 1. 4-1.6 (m, 8 H, OCH2Ctf2CH2CH2), 2.17 (s, 12 H, aryl-CH3), 2.24 (s, 3 H, NCH3), 2.30 (s, 3 H, NCH3), 2.S-2.6 (m, 8 H, NCH2CH2C), 3.02 and 3.36 (AX, J = 12.2 Hz, 4 H, MeN-CH2-Aryl), 3.55-3.8 (m, 8 H, 0CH2CH2CH2CH2Ctf20), 6.46 (d, J = 8.2 Hz, 2 H, DBA-2,10-H),43 6.85 (d, J = 7.3 Hz, 2 H, DBA-4,8-H), 6.90 (s, 4 H, aryl-HDPM), 7.09 (t, J =* 7.8 Hz, 2 H, DBA-3,9-H); MS, m/z (relative intensity) JV,lV,JV ',JV,. A solution of 40.9 g (0.135 mol) of 6,6'-dimethoxydiphenic acid in 100 mL of sulfinyl chloride was heated to reflux for 3 h. The excess of sulfinyl chloride was removed in vacuo.…”

Section: Methodsmentioning

confidence: 99%

“…Results and Discussion A Chiral Barrier from Pyrene and a Host That Acts as Its Own Guest. We found it very attractive to prepare from a planar arene, pyrene (3), a chiral biphenyl barrier incorporated into a macrocyclic host.22 Selective monoozonation of the 4,5-bond of pyrene23 followed by reduction leads to 4,5-phenanthrenedimethanol (4).24 Cyclization of 4 with the dichloride 6 was expected to give the macrocycle 7. Selective ozonation of the 9,10-bond of the phenanthrene moiety of 725 followed by functional group transformations should yield the water-soluble macrocycle 8 with a stable chiral 2,2',6,6'-tetrasubstituted biphenyl barrier.…”

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confidence: 99%

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Chiral recognition in aqueous solution. Search for water-soluble chiral hosts with apolar binding sites

Rubin¹,

Dick

Diederich³

et al. 1986

J. Org. Chem.

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Macrocycles la/b with tetrasubstituted biphenyl units as chiral barriers are designed as potential hosts for the optical resolution of racemic aromatic guests with anionic residues. Synthetic attempts to prepare from a planar arene, pyrene, a chiral biphenyl barrier incorporated into a water-soluble host are presented. On the way to such a macrocycle, the l,7,20,26-tetraoxa[8](4,5)phenanthreno[8.1]paracyclophane 7 was synthesized. Selective ozonolysis of the 9,10-bond of the phenanthrene unit of 7 to generate the chiral barrier was not successful. The phenanthrene unit, according to NMR, is located in the intramolecular cavity of 7 and therefore is protected from attack by ozone. On the way to la, the l,7,20,26-tetraoxa [7](2,2')biphenylo[7.1]paracyclophane 14 with two aminomethyl groups at the 6,expositions of the biphenyl unit was prepared. Eschweiler-Clarke methylation of 14 afforded as major product, besides the macrocyclic tris (tertiary amine) 15, the precursor to la, a macrocycle incorporating a 6,7-dihydro-5Ef-dibenz[c,e]azepine moiety. A possible mechanism of formation of the l,7,19,25-tetraoxa[7](l,ll)-5H-dibenz[c,e]azepino[7.1]paracyclophane 18 is presented. The synthesis of 32,36,7,20,(2,2,)biphenylo[7.1]paracyclophane-33,4Xpiperidine] (20) as nonquaternized precursor to lb is described. Binding studies in acidic aqueous solution with the triprotonated macrocyclic amines 15 and 20 below their critical micelle concentration showed that these macrocycles do not act as hosts for apolar guests.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%