TY  - JOUR
A1  - Jos, Swetha
A1  - Szwetkowski, Connor
A1  - Slebodnick, Carla
A1  - Ricker, Robert
A1  - Chan, Ka Lok
A1  - Chan, Wing Chun
A1  - Radius, Udo
A1  - Lin, Zhenyang
A1  - Marder, Todd B.
A1  - Santos, Webster L.
T1  - Transition Metal‐Free Regio‐ and Stereo‐Selective trans Hydroboration of 1,3‐Diynes: A Phosphine‐Catalyzed Access to (E)‐1‐Boryl‐1,3‐Enynes
JF  - Chemistry – A European Journal
N2  - We report a transition metal‐free, regio‐ and stereo‐selective, phosphine‐catalyzed method for the trans hydroboration of 1,3‐diynes with pinacolborane that affords (E)‐1‐boryl‐1,3‐enynes. The reaction proceeds with excellent selectivity for boron addition to the external carbon of the 1,3‐diyne framework as unambiguously established by NMR and X‐ray crystallographic studies. The reaction displays a broad substrate scope including unsymmetrical diynes to generate products in high yield (up to 95 %). Experimental and theoretical studies suggest that phosphine attack on the alkyne is a key process in the catalytic cycle.
KW  - enediyne
KW  - enyne
KW  - hydroboration
KW  - organocatalytic
KW  - stereoselective
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-293784
VL  - 28
IS  - 63
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  -