103063-81-6Relevant articles and documents
The Reaction of Dihalocarbenes with Quadricyclane
Jefford, Charles William,Roussilhe, Jacques,Papadopoulos, Mihail
, p. 1557 - 1568 (2007/10/02)
The reaction of difluoro-, dichloro- and dibromocarbene with quadricyclane (2) were examined.In all cases, conversions were low (4-15percent), but three distinct reaction courses were observed: cleavage, 1,2-addition, and 1,4-addition.Difluorocarbene gave mainly 6-endo-(2,2-difluorovinyl)-cis-bicyclohex-2-ene (8; 52-89percent relative yield), together with minor amounts of exo-3,3-difluorotricyclo2,4>oct-6-ene (7; 13-17percent), and 4,4-difluorotetracyclo2,8.03,6>octane (5; 2-4percent).Dichlorocarbene gave analogous products, but in relative yields of 35(17), 51(11), and 12percent(16).The product 11 of 1,2-exo addition underwent furtherrearrangement to its allylic derivative 12.A small amount of 1,2-endo addition also occured (2percent of 14/15).Dibromocarbene gave predominantly products derived from rearrangement of the 1,2-exo (61percent of 20/21) and, 1,2-endo adducts (10percent of 23/24).In addition, a significant amount of 4,4-dibromotetracyclo2,8.03,6>octane (25; 21percent) was formed.The cleavage product, 6-endo-(2,2-dibromovinyl)-cis-bicyclohex-2-ene (26) was also observed (7percent).The yields and product compositions were compared to those obtained from norbornadiene (1) and found to be entirely different (Table 1) for example no cleavage occured with difluorocarbene.
REACTIONS OF CARBENES WITH BICYCLOBUTANES AND QUADRICYCLANE CYCLOADDITIONS WITH TWO ? BONDS
Jackson, James E.,Mock, George B.,Tetef, Merry L.,Zheng, Guo-Xiu,Jones, Maitland Jr.
, p. 1453 - 1464 (2007/10/02)
Dicarcomethoxycarbene and dichlorocarbene add to 1,2,2-trimethylbicyclobutane in such a fashion as to suggest a concerted addition in which the central and side bonds are cleaved simultaneously.MNDO calculations support such a pathway and suggest that endo attack on the bicyclobutane is preferred to exo.Reaction of the same two carbenes with quadricyclane gives substituted derivatives of the exo-tricyclo2,4>oct-6-ene system.Although these products rearrange further under the conditions of reaction and/or analysis, they can be shown to be primary products.It is suggested that quadricyclane reacts with carbenes in a concerted fashion.
Sigmatropic Rearrangements Accompanying the Addition of Dichlorocarbene to Norbornadiene
Jefford, Charles W.,Bernardinelli, Gerald,Rossier, Jean-Claude,Zuber, Jacques A.
, p. 1467 - 1469 (2007/10/02)
A new product arising from the reaction of dichlorocarbene with norbornadiene, 6endo-(2,2-dichlorovinyl)-cis-bicyclohex-2-ene, is described.It does not arise from the normal exo-1,2-adduct, but possibly originates by sigmatropic rearrangement of an initially formed zwitterionic intermediate.
