Alkynylphosphine sulfides

Scheme 2.103 Pd-catalyzed annulation of 1-alkynylphosphine sulfides with 2-iodoanilines.

Regioselective hydroamidation of 1-alkynylphosphine sulfides provided (E)-2-amino-l-thiophosphinyl-l-alkenes. Asymmetric hydrogenation led to the corresponding saturated derivative (Scheme 25). ... 

The bulky phosphine ligands were synthesized via [2 + 2 + 2] cycloaddition of diynes with 1-alkynylphosphine sulfides using the cationic rhodium(I)/BINAP catalyst followed by desulfurization (Scheme 4.44) [47]. 

A useful approach to the preparation of bulky arylphosphines is rhodium-catalyzed [2- -2- -2] cycloaddition of 1-alkynylphosphine sulfides to 1,6-diynes followed by removing sulfur, which leads to phosphines with bulky aromatic substituents [102, 103]. Condensation of sulfides 2.153 with diynes 2.152 in the presence of cationic rhodium catalyst and the (R)-binap ligand gives arylphosphine sulfides 2.154 in moderate to good yields (44-97%) (Scheme 2.53) [100, 102, 103]. 

Scheme 2.53 Rhodium-catalyzed formal [2-1-2- -2] cycloaddition reactions of 1-alkynylphosphine sulfides with tethered diynes.

Kondoh, A., Yorimitsu, H. and Oshima, K. (2007) Synthesis of bulky phosphines by rhodium-catalyzed formal [2-1-2- -2] cycloaddition reactions of tethered diynes with 1-alkynylphosphine sulfides. Journal of the American Chemical Society, 129(22), 6996-6997. 

While terminal alkynes are typically used for metal-catalyzed hydrothiolation reactions, the treatment of 1-alkynylphosphines 18 with a variety of thiols in the presence of Pd(OAc)2 resulted in (Z)-isomers 19 through a preferential coordination of the substrate phosphine to a Pd metal center 20 followed by nucleophilic attack of thiol and protonolysis.In 2010, Liu and co-workers reported on the Cu-catalyzed decarboxylative cross-coupling of arylpropiolic acids 21 with thiols for the synthesis of vinyl sulfides 22 with high stereoselectivity for (Z)-isomers. ... 

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