1440433-72-6Relevant academic research and scientific papers
Dealkanative Main Group Couplings across the peri-Gap
Taylor, Laurence J.,Bühl, Michael,Chalmers, Brian A.,Ray, Matthew J.,Wawrzyniak, Piotr,Walton, John C.,Cordes, David B.,Slawin, Alexandra M. Z.,Woollins, J. Derek,Kilian, Petr
, p. 18545 - 18551 (2017)
Here, we highlight the ability of peri-substitution chemistry to promote a series of unique P-P/P-As coupling reactions, which proceed with concomitant C-H bond formation. This dealkanative reactivity represents an interesting and unexpected expansion to the established family of main-group dehydrocoupling reactions. These transformations are exceptionally clean, proceeding essentially quantitatively at relatively low temperatures (70-140 °C), with 100% diastereoselectivity in the products. The reaction appears to be radical in nature, with the addition of small quantities of a radical initiator (azobis(isobutyronitrile)) increasing the rate dramatically, as well as altering the apparent order of reaction. DFT calculations suggest that the reaction involves dissociation of a phosphorus centered radical (stabilized by the peri-backbone) to the P-P coupled product and a free propyl radical, which carries the chain. This unusual reaction demonstrates the powerful effect that geometric constraints, in this case a rigid scaffold, can have on the reactivity of main group species, an area of research that is gaining increasing prominence in recent years.
Peri-substituted phosphino-phosphonium salts: Synthesis and reactivity
Ray, Matthew J.,Slawin, Alexandra M. Z.,Buehl, Michael,Kilian, Petr
, p. 3481 - 3492 (2013/07/26)
The clean reaction of 5-lithio-6-(diisopropylphosphino)acenaphthene with dichlorophosphines RPCl2 gives the peri-substituted phosphino-phosphonium salts [Acenap(PiPr2)(PR)]+Cl - (2, R = Ph; 3, R = Fc; 4, R = NMe2; 5, R = iPr; Acenap = acenaphthene-5,6-diyl). Their ionic structure is maintained in solution and in the solid state. The reduction of 2 and 3 with LiAlH4 led to the formation of mixed tertiary/secondary chelating bis(phosphines) Acenap(PiPr 2)(PRH) (6 and 7), which were subsequently reacted with PtCl 2(cod) to give the complexes [(6)/(7)PtCl2] (8 and 9). Reaction of 2 and 3 with a large excess of MeOTf at elevated temperature gave the chiral 1,2-diphosphoniums [Acenap(PiPr2)(PRMe)] 2+([TfO]-)2 (10 and 11), which were reduced with LiAlH4 to the heteroleptic bis(phosphines) Acenap(PiPr 2)(PRMe) (12 and 13); these were then reacted with [(nor)Mo(CO) 4] to give the complexes [(12)/(13)Mo(CO)4] (14 and 15). The heteroleptic bis(phosphines) 6, 7, 12, and 13 display large through-space couplings (formally 4JPP = 163-199 Hz), comparable in magnitude to 1JPP couplings observed in phosphino-phosphonium salts 2-5 (303-412 Hz). Single-crystal X-ray structures of 2, 3, 7-9, 14, and 15 are reported.
