139688-18-9Relevant articles and documents
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
