TY  - JOUR
A1  - Huang, Mingming
A1  - Hu, Jiefeng
A1  - Shi, Shasha
A1  - Friedrich, Alexandra
A1  - Krebs, Johannes
A1  - Westcott, Stephen A.
A1  - Radius, Udo
A1  - Marder, Todd B.
T1  - Selective, Transition Metal-free 1,2-Diboration of Alkyl Halides, Tosylates, and Alcohols
JF  - Chemistry-A European Journal
N2  - Defunctionalization of readily available feedstocks to provide alkenes for the synthesis of multifunctional molecules represents an extremely useful process in organic synthesis. Herein, we describe a transition metal-free, simple and efficient strategy to access alkyl 1,2-bis(boronate esters) via regio- and diastereoselective diboration of secondary and tertiary alkyl halides (Br, Cl, I), tosylates, and alcohols. Control experiments demonstrated that the key to this high reactivity and selectivity is the addition of a combination of potassium iodide and N,N-dimethylacetamide (DMA). The practicality and industrial potential of this transformation are demonstrated by its operational simplicity, wide functional group tolerance, and the late-stage modification of complex molecules. From a drug discovery perspective, this synthetic method offers control of the position of diversification and diastereoselectivity in complex ring scaffolds, which would be especially useful in a lead optimization program.
KW  - organic synthesis
KW  - boronate esters
KW  - alkyl halides
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318262
VL  - 28
IS  - 24
ER  - 
TY  - JOUR
A1  - Liu, Zhiqiang
A1  - Budiman, Yudha P.
A1  - Tian, Ya‐Ming
A1  - Friedrich, Alexandra
A1  - Huang, Mingming
A1  - Westcott, Stephen A.
A1  - Radius, Udo
A1  - Marder, Todd B.
T1  - Copper‐Catalyzed Oxidative Cross‐Coupling of Electron‐Deficient Polyfluorophenylboronate Esters with Terminal Alkynes
JF  - Chemistry – A European Journal
N2  - We report herein a mild procedure for the copper‐catalyzed oxidative cross‐coupling of electron‐deficient polyfluorophenylboronate esters with terminal alkynes. This method displays good functional group tolerance and broad substrate scope, generating cross‐coupled alkynyl(fluoro)arene products in moderate to excellent yields. Thus, it represents a simple alternative to the conventional Sonogashira reaction.
KW  - boronate esters
KW  - coupling reactions
KW  - fluorine
KW  - fluoroarenes
KW  - Sonogashira reaction
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224362
VL  - 26
IS  - 71
SP  - 17267
EP  - 17274
ER  - 
TY  - JOUR
A1  - Liu, Xiaocui
A1  - Ming, Wenbo
A1  - Luo, Xiaoling
A1  - Friedrich, Alexandra
A1  - Maier, Jan
A1  - Radius, Udo
A1  - Santos, Webster L.
A1  - Marder, Todd B.
T1  - Regio‐ and Stereoselective Synthesis of 1,1‐Diborylalkenes via Brønsted Base‐Catalyzed Mixed Diboration of Alkynyl Esters and Amides with BpinBdan
JF  - European Journal of Organic Chemistry
N2  - The NaOtBu‐catalyzed mixed 1,1‐diboration of terminal alkynes using the unsymmetrical diboron reagent BpinBdan (pin = pinacolato; dan = 1,8‐diaminonaphthalene) proceeds in a regio‐ and stereoselective fashion affording moderate to high yields of 1,1‐diborylalkenes bearing orthogonal boron protecting groups. It is applicable to gram‐scale synthesis without loss of yield or selectivity. The mixed 1,1‐diborylalkene products can be utilized in Suzuki–Miyaura cross‐coupling reactions which take place selectivly at the C–B site. DFT calculations suggest the NaOtBu‐catalyzed mixed 1,1‐diboration of alkynes occurs through deprotonation of the terminal alkyne, stepwise addition of BpinBdan to the terminal carbon followed by protonation with tBuOH. Experimentally observed selective formation of (Z)‐diborylalkenes is supported by our theoretical studies.
KW  - boronate esters
KW  - borylation
KW  - cross‐coupling
KW  - synthesis design
KW  - structure elucidation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214728
VL  - 2020
IS  - 13
SP  - 1941
EP  - 1946
ER  -