Tetramethyldisiloxane (TMDSO, TMDS)
1,1,3,3-tetramethyldisiloxane and 1,2-bis(dimethylsilyl)benzene are found to be effective reducing agents for a platinum-catalyzed reduction of carboxamides to amines. The reaction tolerates other reducible functional groups such as NO2, CO2R, CN, C═C, Cl, and Br. The product is obtained by simple extraction.
S. Hanada, E. Tsutsumi, Y. Motoyama, H. Nagashima, J. Am. Chem. Soc., 2009, 131, 15032-15040.
The combination of amide activation by Tf2O with B(C6F5)3-catalyzed hydrosilylation with TMDS enables a one-pot reduction of secondary amides to amines under mild conditions with broad applicability and excellent chemoselectivity for many sensitive functional groups.
P.-Q. Huang, Q.-W. Lang, Y.-R. Wang, J. Org. Chem., 2016, 81, 4235-4243.
Tris(pentafluorophenyl)boron B(C6F5)3 is an effective catalyst for the reduction of tertiary and N-phenyl secondary amides in the presence of a silane. Various amides can be reduced in near quantitative yield, with minimal purification, at low temperatures, and with short reaction times. This reduction tolerates alkenes, nitro groups, and aryl halides, including aryl iodides.
R. C. Chadwick, V. Kardelis, P. Lim, A. Adronov, J. Org. Chem., 2014, 79, 7728-7733.
A triruthenium cluster catalyzes the reaction of secondary amides with hydrosilanes, yielding a mixture of secondary amines, tertiary amines, and silyl enamines. Production of secondary amines with complete selectivity is achieved by the use of higher concentration of the catalyst and bifunctional hydrosilanes such as 1,1,3,3-tetramethyldisiloxane followed by acidic workup.
S. Hanada, T. Ishida, Y. Motoyama, H. Nagashima, J. Org. Chem., 2007, 72, 7551-7559.
Nanoparticles formed from PdCl2 in the presence of tetramethyldisiloxane (TMDS) on water enable a mild and environmentally attractive dehalogenation of functionalized aryl halides. The reaction medium with the catalyst can be recycled.
A. Bhattacharjya, P. Klumphu, B. H. Lipshutz, Org. Lett., 2015, 17, 1122-1125.
The counteranions of CuCl2 functioned as a chloride source in a reductive chlorination of carboxylic acids in the presence of a gallium(III) catalyst and a hydrosiloxane.
N. Sakai, T. Nakajima, S. Yoneda, T. Konakahara, Y. Ogiwara, J. Org. Chem., 2014, 79, 10619-10623.
The combination of 1,1,3,3-tetramethyldisiloxane (TMDS) and trimethylbromosilane (Me3SiBr) enabled a direct bromination of carboxylic acids in the presence of indium bromide (InBr3) as catalyst. The reducing system was tolerant to several functional groups and produced the corresponding alkyl bromides in very good yields.
T. Moriya, S. Yoneda, K. Kawana, R. Ikeda, T. Konakahara, N. Sakai, Org. Lett., 2012, 14, 4842-4845.
A highly effective indium(III)-catalyzed reductive bromination or iodination of various carboxylic acids with 1,1,3,3-tetramethyldisiloxane (TMDS) and a halogen source tolerates many functional groups. This indium catalytic system is also applicable to the reductive iodination of aldehyded, acyl chlorides, and esters. Furthermore, this reducing system can be applied to the one-pot synthesis of alkyl halides and amine derivatives.
T. Moriya, S. Yoneda, K. Kawana, R. Ikeda, T. Konakahara, N. Sakai, J. Org. Chem., 2013, 78, 10642-10650.
Indium(III)-catalyzed reductive iodination or bromination of carboxylic acids enables a one-pot preparation of alkyl cyanides from carboxylic acids via alkyl iodides or alkyl bromides.
T. Moriya, K. Shoji, S. Yoneda, R. Ikeda, T. Konakahara, N. Sakai, Synthesis, 2013, 45, 3233-3238.
A reducing system combined with InBr3 and 1,1,3,3-tetramethyldisiloxane (TMDS) enables a direct thioetherification of various aromatic carboxylic acids and thiols in a one-pot procedure, whereas a system combined with InI3 and TMDS underwent thioetherification of aliphatic carboxylic acids with thiols.
N. Sakai, T. Miyazaki, T. Sakamoto, T. Yatsuda, T. Moriya, R. Ikeda, T. Konakahara, Org. Lett., 2012, 14, 4366-4369.
TMDS is an efficient hydride source for the reduction of tertiary and secondary phosphine oxides using a catalytic amount of Ti(OiPr)4. All classes of tertiary phosphine oxides, such as triaryl, trialkyl, and diphosphine were effectively reduced.
M. Berthod, A. Favre-Réguillon, J. Mohamad, G. Mignani, G. Docherty, M. Lemaire, Synlett, 2007, 1545-1548.
Phosphine oxides are selectively reduced to phoshphines in the presence of other reducible functional groups such as ketones, esters, and olefins using tetramethyldisiloxane (TMDS) as a mild reducing agent in the presence of copper complexes. Based on this transformation, an efficient one pot reduction/phosphination domino sequence generates functionalized aromatic and aliphatic phosphines in good yields.
Y. Li, S. Das, S. Zhou, K. Junge, M. Beller, J. Am. Chem. Soc., 2012, 134, 9727-9732.
A cobalt-catalyzed hydroazidation of α,α-disubstituted olefins with commercially available azide sources provides tertiary azides in useful yields and tolerates a variety of functional groups.
B. Gaspar, J. Waser, E. M. Carreira, Synthesis, 2007, 3839-3845.
A highly Marknovikov selectiv conversion of various olefins to azides was achieved using a cobalt catalyst, 3 equiv of TsN3 as nitrogen source and simple silanes (PhSiH3, TMDSO).
J. Waser, H. Nambu, E. M. Carreira, J. Am. Chem. Soc., 2005, 127, 8294-8295.