ISSN:
0009-2940
Keywords:
cis-1,2-Diborylalkenes, organo-, halosubstituted
;
cis/trans1,2-Diborylalkenes, organosubstituted, photoisomerization of
;
cis/trans-2-Boryl-1-silylalkenes, organosubstituted, photoisomerization of
;
Diorganoboryl groups of alkenes, or- and pl-B(pz)orbitals
;
Monoborylalkenes, organosubstituted
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Substituted 1,2-Diborylalkenes - Preparation and PhotoisomerizationThe organo(halo)substituted cis-1,2-diborylalkenes cis1-R2BC(R)=C(Et)BEt2 (Z)-1 to (Z)-14 are prepared [route I from Na[R3BC≡CR] and ClBR2; route II from cis1-R3SnC(R)=C(Et)BEt2 and RnBHal3+n′ n=0-2; (Z)-11 (route III): cis1-ClB(Ph)CH=C(Et)BEt2 and Me3SiOMe]. Their 11B-and 13C-NMR data show the degree of pz(B)/(C=C) π overlap and are compared with the corresponding data of the monoboryl alkenes [(Z)-15, 16, (Z)-17, (Z)-23, (Z)-24, (Z)-26], the cis-2-boryl-1-silylalkenes [(E)-18, (E)-19, (E)-27, (E)-28], and the cis-2-boryl-1-stannylalkenes [(E)-20 to (E)-22]. - Compounds (Z)-3, (Z)-4, (Z)-9, (E)-18, and (E)-19 with one or two nearly coplanar pz(B) and pz(C=C) groups (pl1-R2B) are isomerized by UV irradiation to their equilibria with the corresponding trans isomers (E)-3, (E)-4, (E)-9, (Z)-18, and (Z)-19, resp., with one or two nearly orthogonal pz(B) and pz(C=C) groups (or1-R2B). Irradiation of (Z)-9 gives the isomer pair (Z/E)1-iso-9 by a Ph/Et exchange between the two boron atoms.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931260207
