Ji Wu,Ke Cao,Cai-Yan Zhang,Tao-Tao Xu,Xin-Yu Wen,Bo Li,Junxiao Yang
A palladium catalyzed selective B(3)–H activation/oxidative dehydrogenative coupling for the synthesis of bis(o-carborane)s connected with B(3)–B(3′) and B(3)–B(6′) bonds has been developed for the first time. A plausible mechanism involving stepwise activation of B(3)–H and B(3′/6′)–H bonds by PdII and PdIV was proposed. This work is the first example and the most efficient protocol for synthesis of bis(o-carborane)s connected with B(3)–B(3′) and B(3)–B(6′) bonds, which has important reference for design, synthesis, and application of bis(o-carborane)s in related fields.
Herein, we describe the synthesis of a series pincer-type half-sandwich complexes containing selective B(3)-H activation of m -carborane. Four pincer-type complexes containing Cp*M (M = Ir/Rh) and (η 6 -pcym)Ru metal-corner, ionic Cp*M[ m -C 2 B 10 H 9 (CS 2 CH 3 ) 2 ](CF 3 SO 3 ) (M = Ir ( 2 ), Rh ( 3 )), (η 6 -pcym)Ru[ m -C 2 B 10 H 9 (CS 2 CH 3 ) 2 ](CF 3 SO 3 ) ( 4 ) and neutral solvolysis product Cp*Ir[ m -C 2 B 10 H 9 (CS 2 CH 3 )(COS)] (Complex 5 ), have been prepared. The addition reaction of MeO − toward 2 3 and 4 causes the formation of moderately stable neutral unsymmetrical pincer-type complexes Cp*M{ m -C 2 B 10 H 9 (CS 2 CH 3 )[CS(SCH 3 )(OCH 3 )]} (M = Ir ( 6 ), Rh ( 7 )) and (η 6 -pcym)Ru{ m -C 2 B 10 H 9 (CS 2 CH 3 )[CS(SCH 3 )(OCH 3 )]} ( 8 ). The substitution reaction of 2 3 and 4 have also been also explored, unsymmetrical chelate complexes Cp*M( t BuNC)[ m -C 2 B 10 H 9 (CS 2 CH 3 ) 2 ](BPh 4 ) (M = Ir ( 9 ), Rh ( 10 )) can be obtained by using t BuNC and NaBPh 4 . All of these complexes have been characterized, including X-Ray single crystal diffraction, NMR spectroscopy, IR spectroscopy and elemental analysis methods.