Thomas J Christopher, Peters Jonas C
Division of Chemistry and Chemical Engineering, Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125, USA.
Inorg Chem. 2003 Aug 25;42(17):5055-73. doi: 10.1021/ic034150x.
The reaction of dimethyldiaryltin reagents Me(2)SnR(2) (R = Ph (1), p-MePh (2), m,m-Me(2)Ph (3), p-(t)BuPh (4), p-MeOPh (5), p-CF(3)Ph (6)) with BCl(3) provided a high-yielding, simple preparative route to the corresponding diarylchloroboranes R(2)BCl (R = Ph (10), p-MePh (11), m,m-Me(2)Ph (12), p-(t)BuPh (13), p-MeOPh (14), p-CF(3)Ph (15)). In some cases, the desired diarylchloroborane was not formed from an appropriate tin reagent Me(2)SnR(2) (R = o-MeOPh (7), o,o-(MeO)(2)Ph (8), o-CF(3)Ph (9)). The reaction of lithiated methyldiaryl- or methyldialkylphosphines with diarylchloroboranes or dialkylchloroboranes is discussed. Specifically, several new monoanionic bis(phosphino)borates are detailed: [Ph(2)B(CH(2)PPh(2))(2)] (25); [(p-MePh)(2)B(CH(2)PPh(2))(2)] (26); [(p-(t)BuPh)(2)B(CH(2)PPh(2))(2)] (27); [(p-MeOPh)(2)B(CH(2)PPh(2))(2)] (28); [(p-CF(3)Ph)(2)B(CH(2)PPh(2))(2)] (29); [Cy(2)B(CH(2)PPh(2))(2)] (30); [Ph(2)B(CH(2)Pp-(t)BuPh)(2)] (31); [(p-MeOPh)(2)B(CH(2)Pp-(t)BuPh)(2)] (32); [Ph(2)B(CH(2)Pp-CF(3)Ph)(2)] (33); [Ph(2)B(CH(2)P(BH(3))(Me)(2))(2)] (34); [Ph(2)B(CH(2)P(S)(Me)(2))(2)] (35); [Ph(2)B(CH(2)P(i)Pr(2))(2)] (36); [Ph(2)B(CH(2)P(t)Bu(2))(2)] (37); [(m,m-Me(2)Ph)(2)B(CH(2)P(t)Bu(2))(2)] (38). The chelation of diarylphosphine derivatives 25-33 and 36 to platinum was examined by generation of a series of platinum dimethyl complexes. The electronic effects of substituted bis(phosphino)borates on the carbonyl stretching frequency of neutral platinum alkyl carbonyl complexes were studied by infrared spectroscopy. Substituents remote from the metal center (i.e. on boron) have minimal effect on the electronic nature of the metal center, whereas substitution close to the metal center (on phosphorus) has a greater effect on the electronic nature of the metal center.
二甲基二芳基锡试剂Me₂SnR₂（R = Ph (1)、对甲基苯基 (2)、间，间-二甲基苯基 (3)、对叔丁基苯基 (4)、对甲氧基苯基 (5)、对三氟甲基苯基 (6)）与BCl₃反应，为相应的二芳基氯硼烷R₂BCl（R = Ph (10)、对甲基苯基 (11)、间，间-二甲基苯基 (12)、对叔丁基苯基 (13)、对甲氧基苯基 (14)、对三氟甲基苯基 (15)）提供了一条高产率、简便的制备途径。在某些情况下，由合适的锡试剂Me₂SnR₂（R = 邻甲氧基苯基 (7)、邻，邻-二甲氧基苯基 (8)、邻三氟甲基苯基 (9)）无法生成所需的二芳基氯硼烷。讨论了锂化的甲基二芳基膦或甲基二烷基膦与二芳基氯硼烷或二烷基氯硼烷的反应。具体而言，详细介绍了几种新的单阴离子双（膦基）硼酸盐：[Ph₂B(CH₂PPh₂)₂] (25)；[(对甲基苯基)₂B(CH₂PPh₂)₂] (26)；[(对叔丁基苯基)₂B(CH₂PPh₂)₂] (27)；[(对甲氧基苯基)₂B(CH₂PPh₂)₂] (28)；[(对三氟甲基苯基)₂B(CH₂PPh₂)₂] (29)；[Cy₂B(CH₂PPh₂)₂] (30)；[Ph₂B(CH₂P[对叔丁基苯基]₂)₂] (31)；[(对甲氧基苯基)₂B(CH₂P[对叔丁基苯基]₂)₂] (32)；[Ph₂B(CH₂P[对三氟甲基苯基]₂)₂] (33)；[Ph₂B(CH₂P(BH₃)(Me)₂)₂] (34)；[Ph₂B(CH₂P(S)(Me)₂)₂] (35)；[Ph₂B(CH₂P(i)Pr₂)₂] (36)；[Ph₂B(CH₂P(t)Bu₂)₂] (37)；[(间，间-二甲基苯基)₂B(CH₂P(t)Bu₂)₂] (38)。通过生成一系列铂二甲基配合物，研究了二芳基膦衍生物25 - 33和36与铂的螯合作用。通过红外光谱研究了取代的双（膦基）硼酸盐对中性铂烷基羰基配合物羰基伸缩频率的电子效应。远离金属中心（即硼上）的取代基对金属中心的电子性质影响最小，而靠近金属中心（磷上）的取代对金属中心的电子性质影响更大。
