A catalytically asymmetric synthesis of α-(hydroxyalkyl)-tri-n-butylstannanes 1 in good-excellent yields and enantioselectivities (up to 98% e.e.) via addition of ethyl(tri-n-butylstannyl)zinc to aldehydes was achieved. In practice, 1 was isolated after protection as its more stable ester or thiocarbamate (PG). The reagent was prepared from equimolar amounts of tri-n-butylstannyl hydride and Et2Zn in DME so as to avoid contamination by lithium and magnesium ions which suppress enantioselectivity.
Stereospecific Stille Cross-Couplings Using Mn(II)Cl<sub>2</sub>
作者:Rambabu Dakarapu、John R. Falck
DOI:10.1021/acs.joc.7b02780
日期:2018.2.2
Cross-coupling reactions are a staple in organic synthesis, especially for C–C bond formation with sp- and sp2-carbon electrophiles. In recent years, the range of accessible C–C bonds has been extended to stereogenic centers which expedites access to greater molecular complexity. However, these reactions predominantly depend upon late transition metal (LTM) catalysts whose cost, toxicity, and/or environmental
Conjugate addition of α-alkoxystannanes via in situ transmetalation using catalytic CuCN
作者:Rama K. Bhatt、Jianhua Ye、J.R. Falck
DOI:10.1016/0040-4039(96)00710-1
日期:1996.5
CatalyticCuCN mediates the in situ transrnetalation of α-thionocarbamoyl stannanes and subsequent conjugateaddition to α,β-unsaturated carbonyls in the presence of chlorotrimethlysilane at or a little above room temperature.
Stereocontrolled Synthesis of α-Amino-α′-alkoxy Ketones by a Copper-Catalyzed Cross-Coupling of Peptidic Thiol Esters and α-Alkoxyalkylstannanes
作者:Hao Li、Anyu He、John R. Falck、Lanny S. Liebeskind
DOI:10.1021/ol201330j
日期:2011.7.15
A stereocontrolled synthesis of α-amino-α′-alkoxy ketones is described. This pH-neutral copper(I) thiophene-2-carboxylate (CuTC)-catalyzed cross-coupling of amino acid thiolesters and chiral nonracemic α-alkoxyalkylstannanes gives α-amino-α′-alkoxy ketones in good to excellent yields with complete retention of configuration at the α-amino- and α-alkoxy-substituted stereocenters.
Falck; Bhatt, Rama K.; Ye, Jianhua, Journal of the American Chemical Society, 1995, vol. 117, # 22, p. 5973 - 5979
作者:Falck、Bhatt, Rama K.、Ye, Jianhua
DOI:——
日期:——
Pd-catalyzed Cross-Coupling of α-(Acyloxy)-tri-<i>n</i>-butylstannanes with Alkenyl, Aryl, and Heteroaryl Electrophiles
作者:Mohan Goli、Anyu He、J. R. Falck
DOI:10.1021/ol102863u
日期:2011.1.21
Racemic and scalemic alpha-(acyloxy)-tri-n-butylstannanes undergo Pd-catalyzed cross-couplings with alkenyl/aryl/heteroaryl iodides, bromides, and triflates in moderate to good yields in THF at 45 degrees C. Simple aryl iodides and unprotected aza-arenes, two classes of electrophiles that typically react sluggishly, are also good substrates. Cross-couplings proceed with retention of configuration at the alkenyl and stannyl-substituted stereocenters.