3043-60-5Relevant articles and documents
Rearragement and Degradation of Bicyclic Amine-Tetraalkyldiboroxanes
Koester, Roland,Schuessler, Wilhelm,Seidel, Guenter,Blaeser, Dieter,Boese, Roland
, p. 1843 - 1850 (2007/10/02)
The amine-tetraalkyldiboroxanes 1,4,7,7' = Et; 1b: R1,4,7 = Et, R7' = Ph; 1b': R4,7,7' = Et, R1 = Ph; 1c: R1,7,7' = Et, R4 = Ph> react on heating by EtBO elimination and allylborane rearrangement to yield the allyl-aminoboranes Me2NB(Et)CH2C(R4)=C(R7,7') 4,7,7' = Et, 2b/2b': R4 = Et, R7,7' = Et, Ph; 2c: R4 = Ph, R7,7' = Et>: On heating above 60 deg C the diastereomeric syn/anti-1d/1d' (1d: R1,7 =C8H14, R4,7' = Et; 1d': R1,7' = C8H14, R4,7 = Et) give the unsaturated rac-amino-trialkyldiboroxane (rac-3) (X-ray structure analysis) by intramolecular 1,2-deaminoboration. rac-3 is characterized by reaction with (Et2BH)2 and (Et2BD)2 with formation of the 1,2,6-oxadiborinane 5 by evolution of H2 or HD respectively.The intramolecular CH-borylation of rac-3 is compared with those of the thujopsen hydrocarbons I-III. - Key Words: Amine-Diboroxanes, bicyclic / 1,2-Deaminoboration, intramolecular / Deoxy boration / Allyl-aminoboranes, organosubstituted, rearrangement / C-Borylation
Substituted 2,5-Dihydro-1,2,5-oxoniadiboratoles, cis-1,2-Diborylalkenes, and 1,2,5-Oxadiborolanes - Preparation and Characterization
Koester, Roland,Seidel, Guenter
, p. 1351 - 1362 (2007/10/02)
The potassium salts (A: R = R' = Et; B: R2 = C8H14, R' = Me; C: R2 = C8H14, R' = Et) react with various electrophiles (H+, R+, Me3E(IV)+) to form substituted 1,3,2-diboroxanes (1, iso8b) including 1,2,5-oxadiborolanes (2, 4, 6, 9, 10), dialkylvinylboranes (1'), 2,5-dihydro-1,2,5-oxoniadiboratoles (3, 5) and cis-1,2-diborylalkenes (7, 8).In particular, A-C react with HCl (as Me3NHCl/THF or HCl/Et2O) to give O2 (1a; R = Me; 1b: R = Et), R2BCR'= Et; 2b: R2 = R' = Et) and (2a: R,R' = Et; 2b: R2 = C8H14, R' = Me; 2c: R2 = C8H14, R'= Et).With MeI in THF the cyclic compounds (3a) or (4b/4'b: R = Me; 4c/4'c: R = Et) and with Et3O*BF4 in CH2Cl2 the heterocycle (5a) and cis-EtOB(C8H14)C(Et)=C(Et)BEt (5c) and/or (6b: R = Me; 6c: R = Et) are obtained.The reactions of A with ClEl(IV)Me3(El(IV) = Si, Ge, Sn) lead to cis-Et2BC(Et)=CB(Et)OEl(IV)Me3 (El = Si (7a), Ge (8a)) and to cyclic (9a).The salts B and C react with ClEl(IV)Me3 (El(IV) = Si, Ge) to form cis-C8H14BC(R)=C(Et)B(Et)OEl(IV)Me3 (El(IV) = Si: 7b: R = Me; 7c: R = Et; El(IV) = GE: 8b: R= Me, 8c: R = Et).On heating 8b isomerizes to cis-Me3GeC(Me)=C(Et)B(Et)OBC8H14 (iso8b).From B and C with ClSnMe3 the substituted 1,2,5-oxadiborolanes (10b/10'b: R = Me; 10c: R = Et) are obtained together with (C8H14B)2O.Key Words: 1,2,5-Oxoniadiboratoles, 1,5-dihydro-, organo-substituted / 1,2,5-Oxadiborolanes, organo-substituted / 1,3,2-Diboroxanes, substituted with unsaturated residues / Boryl-germyl exchange / cis-1,2-Diborylalkenes, organo-substituted
Reactions of Diphenylphosphane Oxide with Organodiboranes(6) - Structure of a Zwitterionic Compound
Koester, Roland,Tsay, Yi-Hung,Synoradzki, Ludwik
, p. 1117 - 1124 (2007/10/02)
(C6H5)2POB(C2H5)2 (3'a), prepared from diphenylphosphane oxide (C6H5)2P(O)H (1) and activated triethylborane (2a*), reacts with tetraalkyldiboranes(6) (R2BH)2 to form the BH3-addition compounds (C6H5)2P(BH3)OBR2 , 2BR , and 3B .The reaction of bis(9-borabicyclononane) (4c)2 with 1 leads to (C6H5)2POBC8H14 (3'c) or 3'c-4a and (C6H5)2PH (7) or (C6H5)2PH-HBC8H14 (7-4c).The crystalline zwitterionic (C6H5)2P(H)OB3 (X-ray analysis) is isolated from the reaction of 1 with (4a)2.
