Acid-Catalyzed Addition of Phosphine to Olefins

Abstract

small amount of n-octadecyl bromide, 2.74 g. (67%) of unreacted triphenyl-2-phenylethylgermane and 0.63 g. of product boiling over the range 180-185°at 0.005 mm. Recrystallization of this latter fraction from methanol gave 0.5 g. (28.6%) based on unrecovered starting material) of n-octadecyldiphenyl-2-phenylethylgermane, m.p. and mixture m.p. 34.5-35.5°.Cleavage of tri-n-hexylphenylgermane. (Attempted,). A mixture of 2.03 g. (0.005 mole) of tri-n-hexylphenylgermane, 0.3 g. (0.043 g.-atom) of lithium and 7 ml. of ethylene glycol dimethyl ether was stirred for 24 hr. to yield a deep red solution giving a positive Color Test I. The solution was pipetted into a dropping funnel and added to 1.7 g. (0.01 mole) of n-hexyl bromide dissolved in 20 ml. of GDME.After stirring 5 min., Color Test I was negative. Water was added and the mixture extracted with ether. The ether portions were dried and the solvents distilled to leave a residue which was distilled under reduced pressure to give 1.3 g. (65%) of starting material, b.p. 186-188°( 0.7 mm.), 1.4959.

CaII, YbII and SmII Bis(Amido) Complexes Coordinated by NHC Ligands: Efficient Catalysts for Highly Regio‐ and Chemoselective Consecutive Hydrophosphinations with PH3

“…Free NHCs were also found to be able to promote addition of PH 3 to styrene, however they provide much lower reactionr ates comparedt ot he metal complexes.The formation of CÀPb onds by single-step intermolecular hydrophosphination reactions of unsaturated substrates is a promising, atom-efficient route to av ariety of phosphorus-containing compounds. To date, an umber of examples of this transformationh ave been achieved due to acid, [1] base, [2] dtransition, [3] alkaline-earth, [4] andr are-earth metal catalysis. [4a, 5] Radicali nitiation [2a,c, 6] was also reported and is covered in several reviews.…”

“…Ease of synthesis of PH 3 ,i ts low cost (vs. PhPH 2 )a nd availability make it ac ommercially attractive startingc ompound fort he synthesis of phosphines. Hydrophosphination of multiple CÀCb onds with PH 3 becomes feasible under free radical initiation, [8] acid [1] and superbasic [9] conditions, or UV irradiation. [10] However,t his reaction suffers from a lack of selectivity.T he only example of applying late transition metal complexes for catalytic hydrophosphination of activated substrates (acrylonitrile, [11] ethyl acrylate, [12] formaldehyde [13] ) with PH 3 was published by Pringle and co-workers.…”

Hydrophosphination of Unactivated Alkenes, Dienes and Alkynes: A Versatile and Valuable Approach for the Synthesis of Phosphines

“…The first example was given in a patent in 1952 [31]. A few years later, Hoff and Hill reported the addition of PH3 to various alkenes [32]. The reactions were performed in the presence of methanesulfonic acid.…”

Syntheses of bifunctionalized phosphine complexes via ruthenium promoted stepwise hydrophosphination, insertion, hydration, and hydroamination reactions

“…95 P-H + C X The main substrates of hydrophosphination reactions include alkenes, alkynes, and carbonyl compounds. This process proceeded by thermal, [96][97][98] acidic, 99,100 basic, [101][102][103][104] or free radical [105][106][107][108][109][110] pathways. However, the use of transition metal complexes for such reactions often offers vast improvement in rate, selectivity, and stereocontrol.…”