Avoiding Olefin Isomerization During Decyanation of Alkylcyano α,ω-Dienes: A Deuterium Labeling and Structural Study of Mechanism
作者:Giovanni Rojas、Kenneth B. Wagener
DOI:10.1021/jo800640j
日期:2008.7.1
pathway involving decyanation chemistry for the synthesis of pure alkyl α,ω-dienes in quantitative yields is presented. Prior methodologies for the preparation of such compounds required 6−9 steps, sometimes leading to product mixtures resulting from olefin isomerization chemistry. This isomerization chemistry has been eliminated. Deuteration labeling and structural mechanistic investigations were completed
作者:Giovanni Rojas、Travis W. Baughman、Kenneth B. Wagener
DOI:10.1080/00397910701572456
日期:2007.11
Abstract A synthetic pathway that produces alkyl α,ω‐cyanodiolefins in quantitative yield is described, applying chemistry that is based on simple α‐alkylation of alkyl nitriles. Three amide bases, lithium2,2,6,6‐tetramethylpiperidide, lithium diisopropylamide, and sodium amide, are used to create the α‐carbanions that undergo substitution with various alkylating agents. Optimization leads to essentially
Precision Polyethylene: Changes in Morphology as a Function of Alkyl Branch Size
作者:Giovanni Rojas、Bora Inci、Yuying Wei、Kenneth B. Wagener
DOI:10.1021/ja907521p
日期:2009.12.2
precision-branched polyethylene structures, the branch being placed on each 21st carbon and ranging in size from a methylgroup to an adamantyl group. The crystalline unit cell is shifted from orthorhombic to triclinic, depending upon the nature of the precision branch. Further, the branch can be positioned either in the crystalline phase or in the amorphous phase of polyethylene, a morphology change