Palladium-mediated substitution of the closo-B12H12(−2) and nido-7,8-C2B9H12(−1) ions by PMe2Ph: The single-crystal structure studies of 1,7-(PMe2Ph)2-closo-B12H10 and 9-PMe2Ph-nido-7,8-C2B9H11

Methods to produce B–C, B–P, B–N and B–S bonds in boron clusters

“…Treatment of K[nido-7,8-C 2 B 9 H 12 ] with [Pd(PMe 2 Ph) 2 Cl 2 ] in a 2 : 1 ratio in CH 2 Cl 2 at room temperature formed a mixture of 9-B and 10-B substituted n-PMe 2 Ph-7,8-C 2 B 9 H 12 (n = 9, 10) derivates as the zwitterionic dimethylphenylphosphonium of the nido-carborane, similar to that shown in Scheme 2, in overall good yield. 3 Thanks to the participation of Pd it was possible in 1991 to obtain the first example of a coordinating phosphorus attached to a B in the cluster by Teixidor et al (Scheme 3a). 4 Later, 5…”

Electrophile‐Induced Nucleophilic Substitution of the nido‐Dicarbaundecaborate Anion nido‐7,8‐C2B9H12− by Conjugated Heterodienes

“…The residue was suspended in Et 2 O (100 mL) and extracted with water (4 30 mL). The organic phase was dried over MgSO 4 11 The NMe 4 salt of 1 (500 mg, 2.41 mmol) and AlCl 3 (963 mg, 7.22 mmol) were thoroughly mixed. Acetone (30 mL) and N,N-dimethylthioacetamide (MeC(S)NMe 2 , 1.24 g, 12.04 mmol) were added, and the solution was heated to 45 8C overnight.…”

“…Currently, three types of mechanism for substitution reactions with nido ‐7,8‐C 2 B 9 H 12 − have been recognized 3. 4 In electrophilic substitutions, a suitable reagent, for example, N ‐halosuccinimides, organophosphorus or organosulfur halides, attacks the most electron rich boron positions B9 (or B11) with formation of asymmetrically substituted products, 9‐R‐ nido ‐7,8‐C 2 B 9 H 11 − . The mechanism is considered to be similar to electrophilic substitutions in arenes,3 and many examples have been reported including halogenation,5 acylation,6 silylation,7 phosphanylation,8 alkylation,9 sulfonio‐alkylation,10 sulfenylation,11 and formation of 9‐Me 2 S‐nido‐7,8‐C 2 B 9 H 11 12.…”

“…Thus, thioacetamide (MeC(S)NH 2 ) formed the heterodiene MeC(S)N(CMe 2 ) (3) with acetone in situ, which then reacted with 1 to form asymmetric 9-[MeC-(NHiPr)S]-nido-7,8-C 2 B 9 H 11(2). Support for the mechanism was provided by employing N,N-dimethylthioacetamide (MeC(S)NMe 2 ), which is unable to form an imine, to give the expected symmetric product, 10-[MeC(NMe 2 )S]-nido-7,8-C 2 B 9 H 11(4). Analogously, acetyliminium chloride [MeC(O)NH(CPh 2 )]Cl (5) formed in situ from acetyl chloride and benzophenone imine gave 9-and 10-substituted [MeC(NHCHPh 2 )O]-nido-7,8-C 2 B 9 H 11 (6 and 7, respectively) with 1 in THF.…”

“…B NMR (CD 3 CN): d = À37.3 (d, 1 J BH = 142 Hz, B1), À28.5 (d, 1 J BH = 132 Hz, B10), À25.5 (d, 1 J BH = 140 Hz, B6), À22.3 (d, 1 J BH = 150 Hz, B4), À18.2 (m, B3), À17.6 (m, B11), À14.6 (d, 1 J BH = 150 Hz, B2), À7.5 (s, B9), À4.1 (d, 1 J BH = 139 Hz, B5); 13 C{ 1 H} NMR (CD 3 CN): d = 19.5 (CHCH 3 ), 19.6 (CHCH 3 ), 27.8 (CH 3 ), 37.6 (m, cage-CH), 50.7 (CHCH 3 ), 53.5 (m, cage-CH), 197.2 (CH 3 C-(NHiPr)S); IR: 3330 (s, n(NÀH)), 3038 (w, n(cage-CÀH)), 2969 (w, n(CÀH)), 2596 (s), 2558 (s), 2520 (s, all three n(BÀH)), 1676 (s, n(C= N)), 1563 (m), 1383 (m), 1345 (m), 1028 (m), 1016 (m), 801 (m); MS (ESIÀ): m/z 249.1 ([MÀH] À , 100 %); elemental analysis calcd (%) for C 7 H 22 B 9 NS: C 56.18, H 8.90, N 5.61, S 12.84; found: C 56.07, H 8.95, N 5.53, S 12.86. Synthesis of 10-[CH 3 C{N(CH 3 ) 2 }S]-nido-7,8-C 2 B 9 H 11(4) …”