138662-71-2Relevant academic research and scientific papers
Chiral Synthesis via Organoboranes. Part 32. Synthesis of B-(Cycloalk-2-enyl)-diisopinocampheylboranes of High Enantiomeric Purity via the Asymmetric Hydroboration of Cycloalka-1,3-dienes. Successful Asymmetric Allylborations of Aldehydes with B-(Cycloalk-2-enyl)diisopinocampheylboranes
Brown, Herbert C.,Bhat, Krishna S.,Jadhav, Prabhakar K.
, p. 2633 - 2638 (2007/10/02)
The hydroboration of cycloalka-1,3-dienes (CnH2n-4, n = 6, 7 and 8) with diisopinocampheylborane (dIpc2BH or lIpc2BH) at -25 deg C provides highly enantiomerically pure B-(cycloalk-2-enyl)diisopinocampheylboranes, l or dIpc2BCnH2n-3 (>/= 93percent ee).Surprisingly, these allylic borane derivatives retain their stereochemical integrity at -25 deg C although such compounds are capable of undergoing racemization through rapid allylic rearrangements.Furthermore, the B-(cycloalk-2-enyl)diisopinocampheylboranes achieve allylborations of aldehydes at -78 deg C and afford 1-(cycloalk-2-enyl)alkan-1-ols in 90-95percent ee and 100percent syn-diastereoselectivity.
Rotational Barriers of Vinyl-Substituted Olefines
Doering, William von E.,Roth, Wolfgang R.,Bauer, Frank,Boenke, Martin,Breuckmann, Rolf,et al.
, p. 1461 - 1470 (2007/10/02)
For the vinyl-substituted olefines 1-14 activation parameters for the geometrical isomerisation have been determined in the gas-phase.By comparison of these barriers with the corresponding ones of the isolated double bonds, each corrected by the contribution of the steric energy to the ground and transition state, a value of 13.5 +/- 1.1 kcal mol-1 for the allyl stabilisation energy (ASE), defined as replacement of alkyl by vinyl, has been derived.
