593-90-8

Basic information

• Product Name: TRIMETHYLBORON
• Synonyms: Trimethylboroncolorlessgas;Trimethylboronelecgrcolorlessgas;TRIMETHYLBORON, 98.35+%, ELECTRONIC GRAD E;Trimethylboron,98%;Trimethylboron,elec.gr.(99.999%-B)PURATREM;99.9-B, PURATREM;TRIMETHYLBORON, ELEC. GR.;trimethylborine
• CAS NO: 593-90-8
• Molecular Formula: C₃H₉B
• Molecular Weight: 55.91
• EINECS: 209-816-3
• Product Categories: Chemical Synthesis;Compressed and Liquefied GasesVapor Deposition Precursors;Gases;Precursors by Metal;Synthetic Reagents;metal alkyl;Chemical Synthesis;CVD and ALD Precursors by Metal;Materials Science;Micro/NanoElectronics;Specialty Gases;Synthetic Reagents;Vapor Deposition Precursors
• Mol File: 593-90-8.mol
• Article Data: 27

Chemical Properties

• Melting Point: -161,5°C
• Boiling Point: -20,2°C
• Flash Point: °C
• Appearance: /liquid
• Density: 0,625 g/cm3
• Vapor Pressure: 907mmHg at 25°C
• Refractive Index: 1.311
• CAS DataBase Reference: TRIMETHYLBORON(CAS DataBase Reference)
• NIST Chemistry Reference: TRIMETHYLBORON(593-90-8)
• EPA Substance Registry System: TRIMETHYLBORON(593-90-8)

Safety Data

• Hazard Codes: F,C
• Statements: 11-17-34
• Safety Statements: 9-16-23-45-43-36/37/39-26-7
• RIDADR: 3160
• HazardClass: 2.3
• Hazardous Substances Data: 593-90-8(Hazardous Substances Data)

Usage

Uses

Precursor to boron carbide thin films by chemical vapor deposition (CVD).1

InChI:InChI=1/C3H9B/c1-4(2)3/h1-3H3

Synthetic route

(methyl)3boron*NH3 → trimethylborane (593-90-8) + ammonia (7664-41-7)

Conditions	Yield
at 130.0°C, 74.1 Torr equilibrium;	A 99.6% B 99.6%
at 130.0°C, 74.1 Torr equilibrium;	A 99.6% B 99.6%
at 54.8°C, 57.6 Torr equilibrium;	A 90.8% B 90.8%
at 54.8°C, 57.6 Torr equilibrium;	A 90.8% B 90.8%

Triisopropyl borate (5419-55-6) + methyllithium (917-54-4) → dimethylisopropoxyborane + trimethylborane (593-90-8) + diisopropoxymethylborane (86595-27-9)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 1% B <1 C 98%

tri-sec-butylborate (22238-17-1) + methyllithium (917-54-4) → (CH3)2B(OCH(CH3)CH2CH3) + CH3B(OCH(CH3)CH2CH3)2 (86595-29-1) + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 1% B 98% C <1

triisobutyl borate (13195-76-1) + methyllithium (917-54-4) → (CH3)2B(OCH2CH(CH3)2) + CH3B(OCH2CH(CH3)2)2 (86595-30-4) + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 1% B 98% C <1

methyllithium (917-54-4) + 2,4,4,5,5-pentamethyl-[1,3,2]dioxaborolane (94242-85-0) → (CH3)2BOC(CH3)2C(CH3)2OH (97782-68-8) + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether byproducts: LiCl; 1 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, warming to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 98% B <1

trimethyl-borane; compound with trimethylamine (856617-42-0) → trimethylborane (593-90-8) + trimethylamine (75-50-3)

Conditions	Yield
at 111.3°C, 64.5 Torr equilibrium;	A 96% B 96%
at 111.3°C, 64.5 Torr equilibrium;	A 96% B 96%
at 65.8°C, 47.5 Torr equilibrium;	A 63.8% B 63.8%

methyllithium (917-54-4) + diisopropoxymethylborane (86595-27-9) → dimethylisopropoxyborane + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether byproducts: LiCl, 2-propanol; 2 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, warming to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 95% B <1
With hydrogenchloride In diethyl ether byproducts: LiCl, 2-propanol; 1 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, warming to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 95% B <1

methyllithium (917-54-4) + 2-methyl-[1,3,2]dioxaborinane (51901-48-5) → (CH3)2BO(CH2)3OH (765242-40-8) + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether byproducts: LiCl; 2 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, warming to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 92% B <7

bis[tert-butyl(dimethylboryl)amino]methylphosphanoxide (62948-84-9) → trimethylborane (593-90-8) + 1,3-di-tert-butyl-2,4-dimethyl-1,3,2,4-diazaphosphaboretidine-2-oxide (62948-89-4)

Conditions	Yield
In neat (no solvent) heating at 160-170°C for 5 h in a stream of N2 with condensationof the volatiles in a trap cooled at -78°C;; distn.; elem. anal.;;	A 88% B 75%

methylmagnesium bromide (75-16-1) + boron trichloride (10294-34-5) → trimethylborane (593-90-8)

Conditions	Yield
In diethyl ether at room temp. for 2 h, molar ratio BCl3:ether:MeMgBr01:2:3; by fractional condensation;	87%
In diethyl ether at room temp. for 2 h, molar ratio BCl3:ether:MeMgBr01:2:3; by fractional condensation;	87%

dimethylboron bromide (5158-50-9) + bis(tert-butylamino)dimethylsilane (17940-08-8) → trimethylborane (593-90-8) + 1,3-di-tert-butyl-2,2,4-trimethyl-1,3,2,4-diazasilaboretidine (62948-94-1)

Conditions	Yield
With n-butyllithium In hexane; cyclohexane under N2 atmosphere; lithiation of the amine with n-BuLi in hexane; refluxing for 20 h; dropwise addn. of a soln. of B compd. in cyclohexane tothe suspn. of the Li compd. at -78°; slow warming to room temp.;; filtration; removal of volatiles from filtrate; fractional distn.; elem. anal.;;	A 83.5% B 67%

boric acid tributyl ester (688-74-4) + methyllithium (917-54-4) → (CH3)2B(OC4H9) + trimethylborane (593-90-8) + methyldi-n-butoxyborane (86595-28-0)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 9% B <1 C 82%

trimethyl-borane; compound with methylamine (854457-30-0) → trimethylborane (593-90-8) + methylamine (74-89-5)

Conditions	Yield
at 130.0°C, 77.4 Torr equilibrium;	A 81.95% B 81.95%
at 130.0°C, 77.4 Torr equilibrium;	A 81.95% B 81.95%
at 85.4°C, 52.5 Torr equilibrium;	A 38.86% B 38.86%
at 85.4°C, 52.5 Torr equilibrium;	A 38.86% B 38.86%

methylmagnesium bromide (75-16-1) + boron tribromide (10294-33-4) → trimethylborane (593-90-8)

Conditions	Yield
In diethyl ether	80%
In diethyl ether	80%
In benzene
In benzene

2,8-dibromo-3,4,6,7-tetrathia-1-aza-2,5,8-triborabicyclo{3.3.0(1,5)}octane (124665-16-3) + bis(dimethylboryl)disulphane (27484-88-4) → 9-methyl-2,3,5,6,8,10-hexathia-11-aza-1,4,7,9-tetraboratricyclo{6.2.1.0(1,11)}undecane (124665-19-6) + trimethylborane (593-90-8) + dimethylboron bromide (5158-50-9) + 3,5-dimethyl-1,2,4-trithia-3,5-diborolane (25592-09-0)

Conditions	Yield
In toluene N2 atmosphere; addn. of soln. of (Me2BS)2 to soln. of BN(BBr2)2 (room temp., stirring), heating (70°C, 36 h); sepn. of solid, removal of volatiles, sepn. of educt (sublimation, 110°C, 1.3 Pa); elem. anal.;	A 76% B n/a C n/a D n/a

trimethyl-borane; compound with dimethylamine (856622-99-6) → trimethylborane (593-90-8) + dimethyl amine (124-40-3)

Conditions	Yield
at 125.6°C, 66.3 Torr equilibrium;	A 74.2% B 74.2%
at 125.6°C, 66.3 Torr equilibrium;	A 74.2% B 74.2%
at 85.1°C, 45 Torr equilibrium;	A 31.6% B 31.6%
at 85.1°C, 45 Torr equilibrium;	A 31.6% B 31.6%

Triisopropyl borate (5419-55-6) + Trimethylboroxine (823-96-1) → trimethylborane (593-90-8) + diisopropoxymethylborane (86595-27-9)

Conditions	Yield
In tetrahydrofuran	A n/a B 70%

triethyl borate (150-46-9) + methyllithium (917-54-4) → diethoxymethylborane (86595-26-8) + trimethylborane (593-90-8) + Dimethan-borinsaeure-ethylester (86610-16-4)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 65% B 7% C 10%

CH3B(O-t-C4H9)2 (819-38-5) + methyllithium (917-54-4) → trimethylborane (593-90-8) + Dimethylborinsaeure-tert.-butylester (38109-66-9)

Conditions	Yield
With hydrogenchloride In diethyl ether byproducts: LiCl, 2-propanol; 1 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, allowing to warm to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 32% B 58%

tetramethyl diborane (21482-59-7) + ethene (74-85-1) → trimethylborane (593-90-8) + (dimethyl)trifluoropropylborane (819-58-9) + Methyl-bis-<3,3,3-trifluor-propyl>-boran (689-46-3)

Conditions	Yield
	A 30% B 45% C 8%
	A 30% B 45% C 8%

chlorodimethoxyborane (868-81-5) + methyllithium (917-54-4) → trimethylborane (593-90-8) + methoxy-dimethyl-borane (4443-43-0) + bis(methoxy)methylborane (7318-81-2)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 16% B 6% C 43%

boric acid tribenzyl ester (2467-18-7) + methyllithium (917-54-4) → (CH3)2B(OCH2C6H5) + CH3B(OCH2C6H5)2 + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 25% B 42% C 4%

diborane + dimethyl zinc(II) (544-97-8) → zinc dihydride (14018-82-7) + trimethylborane (593-90-8) + methylzinc tetrahydroborate

Conditions	Yield
In neat (no solvent) (exclusion of moisture); room temp., 16 h; purifn. by trap-to-trap distn.;	A n/a B n/a C 40%

Trimethyl borate (121-43-7) + trimethylaluminum (75-24-1) → trimethylborane (593-90-8)

Conditions	Yield
In mineral oil B(OCH3)3 condensed onto Al(CH3)3 soln. with -196°C trap, opened to closed vol., warmed slowly to room temp. with stirring, repeated twice; pumped into -196°C trap, passed through -132°C into -196°C trap;	38%

tetramethyl diborane (21482-59-7) + ethene (74-85-1) → trimethylborane (593-90-8) + dimethylethylborane (1113-22-0) + triethyl borane (97-94-9) + methyldiethylborane (1115-07-7)

Conditions	Yield
	A 25% B 34% C 0.5% D 19%
	A 25% B 34% C 0.5% D 19%

dimethylboron bromide (5158-50-9) + 1,1,1,3,3,3-hexamethyl-disilazane (999-97-3) → trimethylborane (593-90-8) + 2,4,6-Trimethyl-[1,3,5,2,4,6]triazatriborinane (5314-85-2) + bis(dimethylboryl)methylamine (19163-15-6)

Conditions	Yield
byproducts: (CH3)3SiBr; 50°C, 20 h, in closed tube;	A n/a B n/a C 34%

methyllithium (917-54-4) + boron trichloride (10294-34-5) → trimethylborane (593-90-8) + methoxy-dimethyl-borane (4443-43-0) + bis(methoxy)methylborane (7318-81-2)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 32% B 3% C <1

2-bromo-1,3,2-benzodioxaborole (51901-49-6) + methyllithium (917-54-4) → (CH3)2BOC6H4OH (97782-69-9) + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether byproducts: LiCl; 1 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, warming to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 20% B 30%

fluorodimethoxyborane (367-46-4) + methyllithium (917-54-4) → trimethylborane (593-90-8) + methoxy-dimethyl-borane (4443-43-0) + bis(methoxy)methylborane (7318-81-2)

Conditions	Yield
With hydrogenchloride In diethyl ether under N2; to cold (-78 °C) soln. of boron compd. in Et2O slowly added MeLi, stirred for 0.5 h, warmed to room temp., stirred for 0.5 h,Li(BMe4) detected by (11)B NMR, cooled to 0 °C, added soln. of HCl in Et2O, stirred for 15 min, warmed; not isolated, monitored by (11)B NMR;	A 28% B <1 C 10%

methyllithium (917-54-4) + 2-methyl-1,3,2-dioxaborolane (37003-57-9) → (CH3)2BO(CH2)2OH (97782-66-6) + trimethylborane (593-90-8)

Conditions	Yield
With hydrogenchloride In diethyl ether byproducts: LiCl; 1 equiv of MeLi slowly adding to a soln. of the boronic ester at -78°C, stirring for 3 h at the same temp., 1 equiv of anhydrous HCl in Et2O adding, warming to room temp., stirring for 15 min; the content was detd. by (11)B NMR spectrum;	A 21% B 26%

trimethylborane (593-90-8) + imidazolyl sodium (5587-42-8) → Na(1+)*C3H3N2(B(CH3)2)2(1-)*2C4H8O = Na[C3H3N2(B(CH3)2)2]*2C4H8O

Conditions	Yield
In tetrahydrofuran (Ar); warming from -78°C to room temp. (10 h); evapn.; elem. anal.;	99%

trimethylborane (593-90-8) + (tert-butylimino)(2,2,6,6-tetramethylpiperidino)borane (89201-97-8) → [(tert-butyl)(methyl(2,2,6,6-tetramethylpiperidino)boryl)amino]dimethylborane

Conditions	Yield
In hexane	97%
In hexane Schlenk technique, a soln. of iminoborane frozen at -196°C, borancondenced onto it, allowed to slowly thaw, stirred for 4 h; solvent removed (50 Torr); elem. anal.;	97%

boron trioxide + trimethylborane (593-90-8) → Trimethylboroxine (823-96-1)

Conditions	Yield
In neat (no solvent) synthesis of small amounts: condensation of 0.061 mol B(CH3)3 onto 0.061mol B2O3 (-192 °C), heating in a sealed tube at 300°C for 6h;; condensation in vac. into a trap at -78°C;;	96%
In neat (no solvent) synthesis of small amounts: condensation of 0.061 mol B(CH3)3 onto 0.061mol B2O3 (-192 °C), heating in a sealed tube at 300°C for 6h;; condensation in vac. into a trap at -78°C;;	96%

trimethylborane (593-90-8) + dichloroborane (10325-39-0) + boron trichloride (10294-34-5) → dichloro-methyl-borane (7318-78-7)

Conditions	Yield
at ambient temp. 24 h in presence of 1 vol.% HBCl2;	95%
at ambient temp. 24 h in presence of 1 vol.% HBCl2;	95%

trimethylborane (593-90-8) + (S,S)-(-)-1,2-dicyclohexyl-ethane-1,2-diol (120850-91-1) → (4S,5S)-4,5-dicyclohexyl-2-methoxy-1,3,2-dioxaborolane

Conditions	Yield
In neat (no solvent) byproducts: methanol; Ar-atmosphere; stirring; distg.;	95%

trimethylborane (593-90-8) + boron tribromide (10294-33-4) → dimethylboron bromide (5158-50-9)

Conditions	Yield
With alkene; tetraethyldiborane(6) react. of two equiv B(CH3)3 with one equiv BBr3 at room temp., decompn. of catalyst with alkene; distn.;	91%
tetraethyldiborane(6)

trimethylborane (593-90-8) + 2-[bis(2-hydroxyethyl)amino]-1,1-diphenyl-1-ethanol → 3,3-diphenylboratrane (928853-47-8)

Conditions	Yield
In chloroform (Ar), Me3B added to soln. of ligand in CHCl3, stirred for 24 h at room temp.; fconcd.(vac.), pptd.(pentane), filtered, washed (pentane), dried (vac.);	90%

2,3-dimethyl-2,3-butane diol (76-09-5) + trimethylborane (593-90-8) + 1,5-anhydro-2-deoxy-4,6-O-bis(tert-butylsilylidene)-3-O-triisopropylsilyl-D-arabino-hex-1-enitol (262266-33-1) → (1,5-anhydro-2-deoxy-4,6-O-bis(tert-butylsilylidene)-3-O-triisopropylsilyl-D-arabino-hex-1-enitol)boronic acid pinacol ester (842132-50-7)

Conditions	Yield
Stage #1: 1,5-anhydro-2-deoxy-4,6-O-bis(tert-butylsilylidene)-3-O-triisopropylsilyl-D-arabino-hex-1-enitol With n-butyllithium In tetrahydrofuran; hexane at -78 - 0℃; Inert atmosphere; Large scale; Stage #2: trimethylborane In tetrahydrofuran at -78℃; for 1h; Inert atmosphere; Large scale; Stage #3: 2,3-dimethyl-2,3-butane diol In toluene at 20℃; for 12h; Large scale;	90%

trimethylborane (593-90-8) + methyl 4-hydroxy-1-chloro-7-phenoxyisoquinoline-3-carboxylate (1421312-33-5) → 1-methyl-4-hydroxy-7-phenoxyisoquinoline-3-carboxylic acid (1421312-35-7)

Conditions	Yield
Stage #1: trimethylborane; methyl 4-hydroxy-1-chloro-7-phenoxyisoquinoline-3-carboxylate With bis-triphenylphosphine-palladium(II) chloride; sodium phosphate In 2-methoxy-ethanol; water at 90 - 100℃; for 4h; Stage #2: With hydrogenchloride In water at 20 - 30℃; pH=2 - 3;	88%

trimethylborane (593-90-8) + trimethylsilyllithium (18000-27-6) → Li(1+)*B(Si(CH3)3)(CH3)3(1-)=Li{B(Si(CH3)3)(CH3)3} (72442-81-0)

Conditions	Yield
In hexane at -196°C in high vac., pptn. during warming up; the solvent was decanted, the product was washed with pentane, then dissolved in benzene and crystd. with pentane; elem. anal.;	86%

trimethylborane (593-90-8) + methyl (4-hydroxy-1-chloro-7-phenoxyisoquinoline-3-carboxamido)acetate → [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid

Conditions	Yield
With tetrakis(triphenylphosphine) palladium(0); water; potassium carbonate In ethanol at 110℃; for 4h;	86%

dodecacarbonyl-triangulo-triruthenium (15243-33-1) + trimethylborane (593-90-8) + potassium hydride → K(1+)*HRu3(CO)11(1-)=KHRu3(CO)11 (80662-65-3)

Conditions	Yield
In tetrahydrofuran byproducts: CO; distg. of THF onto mixt. of Ru3(CO)12 and KH at -78°C in inert atmosphere, distg. of B(CH3)3 at -196°C, warming to 25°C, CO evolves, the soln. turns bright red; evapn. in vac. after 2 h, dissolving in min. amt. of CH2Cl2, addn. of hexane, filtn., washing (hexane);	83%

trimethylborane (593-90-8) + erythro-2-[bis(2-hydroxyethyl)amino]-1,2-diphenyl-1-ethanol → erythro-3,4-diphenylboratrane

Conditions	Yield
In chloroform (Ar), Me3B added to soln. of ligand in CHCl3, stirred for 24 h at room temp.; filtered, washed (CHCl3), dried (vac.);	82%

trimethylborane (593-90-8) + 1-phenyl-2-methylpropane (538-93-2) + Ethyl oxalyl chloride (4755-77-5) → ibuprofen (15687-27-1)

Conditions	Yield
Stage #1: 1-phenyl-2-methylpropane; Ethyl oxalyl chloride With aluminum (III) chloride Stage #2: trimethylborane With phosphorous acid trimethyl ester Stage #3: With lithium hydroxide	82%

trimethylborane (593-90-8) + (dimethylamino)dimethylphosphine (683-84-1) → Tetramethylborazen (1113-30-0)

Conditions	Yield
byproducts: (CH3)3B*P(CH3)3; in 77 day;	78%
byproducts: (CH3)3B*P(CH3)3; in 77 day;	78%

2,3-dimethyl-2,3-butane diol (76-09-5) + trimethylborane (593-90-8) + diisopropylamine (108-18-9) + 1,2-dibromomethane (74-95-3) → 2-(dibromomethyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (87921-48-0)

Conditions

Yield

With n-butyllithium; hydrogen bromide In tetrahydrofuran; diethyl ether; hexane (i-Pr)2NH in ether mixed with n-BuLi in n-hexane at 0°C, THF added, cooled to -100°C, CH2Br2 in THF added under stirring over 1 h, kept for 30 min at this temp., BMe3 added, after 40 min aq. HBr added at -100°C, warmed to room temp.; filtered, washed (ether), concd., residue taked up (ether), Me2C(OH)C(OH)Me2 added, petroleum ether added, stirred for 1 h, org. phase separated and washed (H2O, 4 times), dried (Na2SO4), concd., distilled at 0.5 Torr (100-110°C); elem. anal.;

77%

Upstream product

• 121-43-7 Trimethyl borate 
• 5419-55-6 Triisopropyl borate 
• 823-96-1 Trimethylboroxine 
• 7637-07-2 boron trifluoride 
• 75-24-1 trimethylaluminum 
• 10294-34-5 boron trichloride 
• 10294-33-4 boron tribromide 
• 688-74-4 boric acid tributyl ester 
• 74-87-3 methylene chloride 
• 917-65-7 methylaluminum dichloride 
• 917-64-6 methyl magnesium iodide 
• 353-46-8 (dimethyl)fluoroborane 
• 544-97-8 dimethyl zinc(II) 
• 23777-55-1 methyl diborane 

Downstream Products

• 100-41-4 ethylbenzene 
• 108-88-3 toluene 
• 13061-96-6 dihydroxy-methyl-borane 
• 823-96-1 Trimethylboroxine 
• 19163-04-3 Dimethylborinsaeure-anhydrid 
• 373-64-8 (methyl)difluoroborane 
• 21127-95-7 2-methyl-borazine 
• 23208-27-7 B-dimethylborazole 
• 5314-85-2 2,4,6-Trimethyl-[1,3,5,2,4,6]triazatriborinane 
• 854457-49-1 B(CH₃)N(C₆H₅) 
• 854457-41-3 B-Trimethyl-N-Phenylborazan 
• 4079-94-1 2,2,3,5,5,6-hexamethyl-1,4-diphenyl-1,4-dihydro-[1,4,2,5]diazadiborinine 
• 3657-04-3 2,3,3,5,6,6-hexamethyl-1,4-diphenyl-[1,4,2,5]diazadiborinane 
• 2169-38-2 lithium tetramethylborate^(1-) 

Relevant articles and documents

Reaction of the Simmons-Smith reagent with trimethylamine-borane

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Indirect nuclear spin-spin coupling constants 1J( 17O,11B). First observation and calculation using density functional theory (DFT)

Coupling constants 1J(17O,11B) of borates, borane adducts and boranes with boron-oxygen bonds have been calculated on the basis of optimised molecular structures using the B3LYP/6-311+G(d,p) level of theory. This indicates that such coupling constants can be of either sign and that their magnitudes can be rather small. Since both 11B and 17O are quadrupole nuclei, it is therefore difficult to measure representative data. In the cases of trimethoxyborane and tetraethyldiboroxanes, it proved possible to obtain experimental data 1J( 17O,11B) (22 and 18 Hz) by measurement of 17O NMR spectra at high temperature (120 °C and 160 °C) respectively. The magnitude of these coupling constants is in reasonable agreement with calculated data. In the case of the diboroxane, this points towards a bond angle B-O-B more close to 180° than to 140°.

Nickel-Catalyzed CO2Rearrangement of Enol Metal Carbonates for the Efficient Synthesis of β-Ketocarboxylic Acids

4-Methylene-1,3-dioxolan-2-ones underwent oxidative addition of a Ni0catalyst in the presence of Me2Al(OMe), followed by a coupling reaction with alkynes, to form δ,?-unsaturated β-ketocarboxylic acids with high regio- and stereoselectivity. The reaction proceeds by [1,3] rearrangement of an enol metal carbonate intermediate and the formal reinsertion of CO2.

Nucleophilicity of Alkyl Zirconocene and Titanocene Precatalysts, and Kinetics of Activation by Carbenium Ions and by B(C6F5)3

Kinetics of activation of methyl and benzyl metallocene precatalysts by benzhydrylium ions, tritylium ions, and triarylborane B(C6F5)3were measured spectrophotometrically. The rate constants correlate linearly with the electrophilicity parameter E of the benzhydrylium and tritylium ions employed, allowing us to determine the σ-nucleophilicities of the metal–carbon bond of several zirconocenes and titanocenes. Bridging, substitution, metal, and ligand effects on the rates of metal–alkyl bond cleavage (M=Zr, Ti) were studied and structure–reactivity correlations were used to predict the kinetics of generation of metallocenium ions pairs, which are active catalysts in polymerization reactions and are highly electrophilic Lewis acids in frustrated Lewis pair catalysis.