9-Borabicyclo nonane-9-thiol

The thioboration of terminal alkynes with 9-(alkylthio)-9-borabicyclo[3.3.1]-nonanes (9-RS-9-BBN) proceeds regio- and stereoselectively by catalysis of Pd(Ph,P)4 to produce the 9-[(Z)-2-(alkylthio)-l-alkeny)]-9-BBN derivative 667 in high yields. The protonation of the product 667 with MeOH affords the Markownikov adduct 668 of thiol to 1-alkyne. One-pot synthesis of alkenyl sulfide derivatives 669 via the Pd-catalyzed thioboration-cross-coupling sequence is also possible. Another preparative method for alkenyl sulfides is the Pd-catalyzed cross-coupling of 9-alkyl-9-BBN with l-bromo-l-phe-nylthioethene or 2-bromo-l-phenylthio-l-alkene[534]. 

Characteristic addition compounds are prepared from the components, e.g. pyridine(N-B)9-borabicyclo[3.3.1]nonane-9-thiol, white solid with mp... 

In order to confer the calixarenes the ability to form SAMs on metal surfaces, they have to be chemically modified to introduce chemical functions (e.g., thiol, thioether, disulfide) able of chemisorption on the surface. Reinhoudt published the synthesis of calix[4]arenes bearing four di- -decyl sulfide chains at the lower rims. The synthesis proceeds via first the alkylation of the calix[4]arene-25,26,27,28-tetrol with 10-undecen-l-yl tosylate followed by the anti-Markovnikov addition of 1-dodecanthiol in the presence of 9-borabicyclo[3.3.1]nonane (9-BBN) (Fig. 37.11) [64]. Similarly to calix[4]arenes, resorcin[4]arenes tetrasulfides have been produced by the condensation reaction of resorcinol and 11-undecylenic aldehyde followed by the addition of 1 -dodecanthiol to the terminal double bonds of the alkyl chains using catalytic amounts of 9-BBN [63]. 

---