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cessful. Attempts to obtain 4 under somewhat altered reaction
conditions (reactive crystallization, different solvents, different con-
centrations, and different stoichiometries) were unsuccessful and
only 3 was isolated after crystallization. Elemental analysis calcd
(%) for C28H57O11B2K: C 53.34, H 9.11, N 0.00; found: C 53.48, H 9.01,
N 0.00.
(overlapping with THF, 8H; NCH2CH2CH2CH3), 1.47 (apparent sextet,
3J(H,H)=7 Hz, 8H; NCH2CH2CH2CH3), 1.08 (brs, 24H; C(CH3)),
1.00 ppm (t, 3J(H,H)=7 Hz, 12H; NCH2CH2CH2CH3); 1H NMR
(700 MHz, [D8]THF, À408C): d=3.55 (brs, 8H; NCH2CH2CH2CH3),
1.70 (brs, 8H; NCH2CH2CH2CH3), 1.48–1.41 (brm, 8H;
NCH2CH2CH2CH3), 1.11 (s, 12H; C(CH3)), 1.04 (s, 6H; C(CH3)), 1.00 (t,
3J(H,H)=7 Hz, 12H; NCH2CH2CH2CH3), 0.94 ppm (s, 6H; C(CH3));
13C NMR (175 MHz, [D8]THF, 258C): d=80.4 (br), 77.9 (br), 58.9, 26.5
(br), 25.3 (overlapping with THF signal), 20.8, 14.6 ppm; 11B NMR
(224 MHz, [D8]THF, 258C): d=31.4 (vbrs), 5.1 ppm (brs); 19F NMR
(658 MHz, [D8]THF, 258C): d=À129.5 ppm (s); 13C SS-NMR
(100 MHz, 258C): d=80.4, 77.9, 76.9, 58.4, 58.9, 27.9, 27.5, 26.1,
25.6, 25.2, 24.4, 24.0, 21.2, 19.9, 19.7, 15.0, 14.4, 13.5 ppm; 19F SS-
NMR (658 MHz, 258C): d=À127.3 ppm; elemental analysis calcd
(%) for C28H60O4NB2F: C 65.25, H 11.73, N 2.72; found: C 65.10, H
11.55, N 2.92.
[K(18-crown-6)][(B2pin2)OMe] (5): Under a nitrogen atmosphere,
KOMe (33 mg, 470 mmol, 2 equiv) and 18-crown-6 (125 mg,
473 mmol, 2 equiv) were dissolved in dry THF (3 mL), aided by stir-
ring. After about 10 min of stirring, 1 (60 mg, 236 mmol, 1 equiv)
was added and the resulting clear solution was stirred overnight at
rt. After concentration under reduced pressure to a volume of ap-
proximately 1 mL, the residue was layered with n-hexane and crys-
tallized at À208C to give 5 (129 mg, 220 mmol, 93%) as colorless
crystals, suitable for X-ray crystallography. M.p. 84–878C; 1H NMR
(500 MHz, [D8]THF, 258C): d=3.62 (s, 24H; OCH2), 3.11 (s, 3H;
OCH3), 1.06 ppm (brs, 24H; C(CH3)); 1H NMR (500 MHz, [D8]THF,
À558C): d=3.64 (s, 24H; OCH2), 3.16 (s, 3H; OCH3), 1.08 (s, 12H;
C(CH3)), 1.03 (s, 6H; C(CH3)), 0.98 ppm (s, 6H; C(CH3)); 13C NMR
(125 MHz, [D8]THF, 258C): d=80.1, 77.3, 71.0, 50.6, 27.4, 27.0,
25.9 ppm; 11B NMR (160 MHz, [D8]THF, 258C): d=37.5 (vbrs),
5.8 ppm (brs); 11B NMR (160 MHz, [D8]THF, À558C): d=6.4 ppm
(brs); 13C SS-NMR (100 MHz, 258C): d=80.1, 77.8, 77.6, 70.9 (br),
51.5, 29.9, 27.7, 27.0, 26.8, 26.1, 25.6 ppm; elemental analysis calcd
(%) for C25H51O11B2K: C 51.03, H 8.74, N 0.00; found: C 51.24, H
8.76, N 0.00.
[Me4N][B2pin2F] (8): Under
a nitrogen atmosphere, [Me4N]F
(257 mg, 2.76 mmol) and 1 (700 mg, 2.76 mmol) were combined in
dry THF (60 mL). After 16 h stirring at 708C, the precipitate was col-
lected by filtration and washed with dry THF (25 mL). The residue
was crystallized from acetonitrile to give 8 (565 mg, 163 mmol,
60%) as a colorless crystalline solid. Recrystallization from THF by
somewhat elaborate conditions [flame-sealed ampoule, heating to
1008C over 2 h, holding at 1008C for 4 h, and finally slow cooling
to rt (150 h)] gave well-developed needles of 8(thf). 1H NMR
(500 MHz, [D3]MeCN, 258C): d=1.03 (s, 24H; C(CH3)), 3.14 ppm (t,
3J(N,H)=0.6 Hz, 12H; N(CH3)4); 1H NMR (200 MHz, [D3]MeCN,
À308C): d=3.10 (s, 12H; N(CH3)4), 1.04 (s, 12H; C(CH3)), 0.96 (s,
6H; C(CH3)), 0.88 ppm (s, 6H; C(CH3)); 13C NMR (175 MHz,
[D3]MeCN, 258C): d=78.9 (br, C(CH3)), 56.1 (t, 1J(N,C)=4 Hz,
N(CH3)4), 26.2 ppm (C(CH3)); 11B NMR (160 MHz, [D3]MeCN, 258C):
d=33.9, (vbrs), 5.7 ppm (brs); 19F NMR (188 MHz, [D3]MeCN, 258C):
d=À125.6 ppm (s); 13C SS-NMR (100 MHz, 258C): d=80.2 (br,
C(CH3)), 77.0 (br; C(CH3)), 54.9 (N(CH3)4), 25.9 ppm (br; C(CH3));
19F SS-NMR (376 MHz, 258C): d=À130.6 ppm; elemental analysis
calcd (%) for C16H36O4NB2F: C 55.37, H 10.45, N 4.04; found: C
55.24, H 10.67, N 4.35.
K[B2pin2O(4-tBuC6H4)] (6): Under a nitrogen atmosphere, KO-
(tBuC6H4) (148 mg, 790 mmol) and 1 (200 mg, 790 mmol) were com-
bined in dry THF (6 mL). After 16 h of stirring at rt, the precipitate
was collected by centrifugation, washed with dry THF (23 mL),
and dried under vacuum to give (6)thf (302 mg, 586 mmol, 74%) as
a colorless solid. M.p. >2408C (decomp.); 1H NMR (700 MHz,
[D7]DMF, 258C): d=6.97 (d, 3J(H,H)=9 Hz, 2H; CH), 6.74 (d,
3J(H,H)=9 Hz, 2H; CH), 3.65–3.62 (m, 4H; THF), 1.80–1.78 (m, 4H;
THF), 1.21 (s, 9H; tBu), 1.05 ppm (s, 24H; C(CH3)); 1H NMR
3
(500 MHz, [D7]DMF, À558C): d=7.01 (brd, J(H,H)=10 Hz, 2H; CH),
6.80 (brs, 2H; CH), 3.67–3.63 (m, 4H; THF), 1.82–1.76 (m, 4H; THF),
1.21 (s, 9H; tBu), 1.04 ppm (brs, 24H; C(CH3)); 13C NMR (125 MHz,
[D7]DMF, 258C): d=161.9, 137.2, 125.7, 118.8, 80.4, 68.4, 34.4, 32.6
(br), 26.4, 26.2 ppm; 11B NMR (224 MHz, [D7]DMF, 258C): d=
22.1 ppm (brs); 11B NMR (224 MHz, [D7]DMF, À558C): d=5.7 ppm
(brs); 13C SS-NMR (100 MHz, 258C): d=159.9, 139.4, 125.1 (br),
118.5 (br), 81.9, 79.1, 77.7, 68.5, 34.2, 32.5, 27.5, 27.0, 26.4, 25.7,
25.4 ppm; elemental analysis calcd (%) for C22H37O5B2K·C4H5O: C
60.71, H 8.82, N 0.00; found: C 60.75, H 8.90, N 0.00. Crystals of
6(dmf) suitable for XRD analysis were obtained by diffusion of di-
ethyl ether into a solution of (6)thf in DMF at 08C. M.p. >2408C
(decomp.); 13C SS-NMR (100 MHz, 258C): d=161.8, 160.3, 139.4,
125.2 (br), 119.6 (br), 81.6, 78.4, 77.4, 36.7, 34.1, 32.1, 30.6, 27.2,
26.7, 26.1, 25.3 ppm; elemental analysis calcd (%) for
C22H37O5B2K·C3H7ON: C 58.27, H 8.61, N 2.72; found: C 58.37, H
8.60, N 2.77.
[K(18-crown-6)][dmedaB-B(OMe)3] (9): Under a nitrogen atmos-
phere, KOMe (35 mg, 499 mmol, 1 equiv), 18-crown-6 (140 mg,
530 mmol, 1.1 equiv), and B2dmeda2 (51 mg, 490 mmol, 1 equiv)
were dissolved in dry THF (4 mL), aided by stirring. After 16 h, the
cloudy solution was filtered through a pad of Celite, concentrated
under vacuum to a volume of approximately 2 mL, and layered
with n-hexane (7 mL). After crystallization at À208C, colorless crys-
tals suitable for XRD analysis were obtained and dried under
vacuum to give 9(thf) (52 mg, 103 mmol, 62% with KOMe as the
1
stoichiometrically limiting starting material). M.p. 68–728C; H NMR
(500 MHz; [D8]THF, 258C): d=3.60 (s, 26H; CH2O (18-crown-6,
THF)), 3.03 (s, 9H; 3OMe), 2.98 (s, 4H; NCH2), 2.88 (s, 6H; NMe),
1.78 ppm (s, 2H; THF); 13C NMR (125 MHz, [D8]THF, 258C): d=71.4,
67.5, 54.2, 48.9, 36.6, 26.6 ppm; 11B NMR (160 MHz, [D8]THF, 258C):
d=35.9 (vbrs), 4.3 ppm (brs); elemental analysis calcd (%) for
C19H43O9N2B2K·1= C4H8O: C 46.68, H 8.77, N 5.18; found: C 46.61, H
[nBu4N][B2pin2F] (7): Under a nitrogen atmosphere, nBu4N·3H2O
(429 mg, 1.35 mmol, 2 equiv) and 1 (180 mg, 702 mmol, 1 equiv)
were combined in dry THF (5 mL). After 16 h stirring at rt, the mix-
ture was concentrated under vacuum until turbid, then crystallized
at À208C to give crystals suitable for XRD analysis. The solvent
was decanted and the crystals were washed with n-hexane (3
2 mL) and dried under vacuum to give 7 (239 mg, 463 mmol, 66%)
as a colorless solid. M.p. 125–1288C; 1H NMR (700 MHz, [D8]THF,
258C): d=3.53 (m, 3J(H,H)=8 Hz, 8H; NCH2CH2CH2CH3), 1.76–1.67
2
8.71, N 4.92.
Procedure for the reaction of 4-MeC6H4I with Lewis base ad-
ducts: The reactions were performed by mixing freshly prepared
solutions (0.15 mL each) of 4-MeC6H4I (46 mmol) and adduct
(46 mmol) in the required solvent in a J. Young NMR tube and addi-
tion of more solvent to give a total volume of 0.6 mL). Only analyti-
cally pure compounds (determined by CHN analysis) were used
Chem. Eur. J. 2015, 21, 7082 – 7099
7095
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